Immunoglobulin like domain pfam13895
The United States National Library of Medicine (NLM) is a biomedical library in the United States as part of the National Institutes of Health that contains "hierarchical classifications of widely distributed protein domain families  conserved sites associated with molecular function, so that they can be mapped onto user queries in support of hypothesis-driven biomolecular research."
"At the time of writing, the CDD version v3.17 is the live production version with 52,910 protein- and protein domain-models obtained from Pfam (1), SMART (2), the COGs collection (3), TIGRFAMS (4), the NCBI Protein Clusters collection (5), NCBIfam (6) and CDDs in-house data curation effort (7)."

# Immunoglobulin supergene family
The immunoglobulin supergene family is "the group of proteins that have immunoglobulin-like domains, including histocompatibility antigens, the T-cell antigen receptor, poly-IgR, and other proteins involved in the vertebrate immune response (17)."

# Alpha-1-B glycoprotein variants
Gene ID: 1 A1BG alpha-1-B glycoprotein on 19q13.43: "The protein encoded by this gene is a plasma glycoprotein of unknown function. The protein shows sequence similarity to the variable regions of some immunoglobulin supergene family member proteins."
"1B-glycoprotein(1B)  consists of a single polypeptide chain N-linked to four
glucosamine oligosaccharides. The polypeptide has five intrachain disulfide bonds and contains 474 amino acid residues.  1B exhibits internal duplication and consists of five repeating structural domains, each containing about 95 amino acids and one disulfide bond.  several domains of 1B, especially the third, show statistically significant homology to variable regions of certain immunoglobulin light and heavy chains. 1B  exhibits sequence similarity to other members of the immunoglobulin supergene family such as the receptor for transepithelial transport of IgA and IgM and the secretory component of human IgA."
"Some of the domains of 1B show significant homology to variable (V) and constant (C) regions of certain immunoglobulins. Likewise, there is statistically significant homology between 1B and the secretory component (SC) of human IgA (15) and also with the extracellular portion of the rabbit receptor for transepithelial transport of polymeric immunoglobulins (IgA and IgM). Mostov et al. (16) have called the later protein the poly-Ig receptor or poly-IgR and have shown that it is the precursor of SC."
"1B-glycoprotein(1B)  consists of a single polypeptide chain N-linked to four
glucosamine oligosaccharides. The polypeptide has five intrachain disulfide bonds and contains 474 amino acid residues.  1B exhibits internal duplication and consists of five repeating structural domains, each containing about 95 amino acids and one disulfide bond.  several domains of 1B, especially the third, show statistically significant homology to variable regions of certain immunoglobulin light and heavy chains. 1B  exhibits sequence similarity to other members of the immunoglobulin supergene family such as the receptor for transepithelial transport of IgA and IgM and the secretory component of human IgA."
A1BG contains the immunoglobulin domain: cl11960 and three immunoglobulin-like domains: pfam13895, cd05751 and smart00410 in the order and nucleotide sequence: cd05751 Location: 401  493, smart00410 Location: 218  280, pfam13895 Location: 210  301 and cl11960 Location: 28  110.
"This domain  contains immunoglobulin-like domains."

# Carcinoembryonic antigen gene family

# Immunoglobulin superfamily genes

# Major histocompatibility complex genes

## Class I

## Class II

## Class III

## Immunoglobulin domain genes

## Immunoglobulin receptor superfamily

# Genes having immunoglobulin like domain pfam13895
Number of genes = 51.
Gene ID: 1 see Immunoglobulin domain genes.
Gene ID: 177 see Major histocompatibility complex class III gene family.
Gene ID: 634 see Carcinoembryonic antigen gene family.
Gene ID: 942 is CD86 CD86 molecule on 3q13.33: "This gene encodes a type I membrane protein that is a member of the immunoglobulin superfamily. This protein is expressed by antigen-presenting cells, and it is the ligand for two proteins at the cell surface of T cells, CD28 antigen and cytotoxic T-lymphocyte-associated protein 4. Binding of this protein with CD28 antigen is a costimulatory signal for activation of the T-cell. Binding of this protein with cytotoxic T-lymphocyte-associated protein 4 negatively regulates T-cell activation and diminishes the immune response. Alternative splicing results in several transcript variants encoding different isoforms."
- NP_001193853.1 T-lymphocyte activation antigen CD86 isoform 4 precursor: "Transcript Variant: This variant (4) lacks an alternate in-frame exon compared to variant 1. The resulting isoform (4) has the same N- and C-termini but is shorter compared to isoform 1." Conserved Domains (1) summary: cl11960 Location: 24  109 Ig; Immunoglobulin domain.
- NP_001193854.1 T-lymphocyte activation antigen CD86 isoform 5: "Transcript Variant: This variant (5) lacks an alternate coding exon compared to variant 1, that causes a frameshift. The resulting isoform (5) is made from a downstream translation start site compared to isoform 1." Conserved Domains (1) summary: cl11960 Location: 2  31 Ig; Immunoglobulin domain.
- NP_008820.3 T-lymphocyte activation antigen CD86 isoform 2 precursor: "Transcript Variant: This variant (2) includes an alternate exon in the 5' UTR, resulting in the use of a downstream start codon compared to variant 1. Isoform 2 has a shorter N-terminus than isoform 1." Conserved Domains (2) summary: smart00406 Location: 29  104 IGv; Immunoglobulin V-Type and smart00410 Location: 28  104 IG_like; Immunoglobulin like.
- NP_787058.5 T-lymphocyte activation antigen CD86 isoform 1 precursor: "Transcript Variant: This variant (1) encodes the longest isoform (1) of this protein." Conserved Domains (2) summary: cd16087 Location: 28  133 IgV_CD86; Immunoglobulin variable domain (IgV) in CD86 and cl11960 Location: 136  221 Ig; Immunoglobulin domain.
- NP_795711.1 T-lymphocyte activation antigen CD86 isoform 3 precursor: "Transcript Variant: This variant (3) includes an alternate exon in the 5' UTR, resulting in the use of a downstream start codon compared to variant 1. It also lacks an in-frame exon compared to variant 1. The resulting isoform (3, also known as CD86deltaTM) has a shorter N-terminus and lacks an internal segment compared to isoform 1. This isoform is the soluble form of this protein." Conserved Domains (3) summary: smart00406 Location: 29  104 IGv; Immunoglobulin V-Type, smart00410 Location: 28  104 IG_like; Immunoglobulin like, and pfam13895 Location: 133  228 Ig_2; Immunoglobulin domain.
Gene ID: 962 is CD48 CD48 molecule on 1q23.3: "This gene encodes a member of the CD2 subfamily of immunoglobulin-like receptors which includes SLAM (signaling lymphocyte activation molecules) proteins. The encoded protein is found on the surface of lymphocytes and other immune cells, dendritic cells and endothelial cells, and participates in activation and differentiation pathways in these cells. The encoded protein does not have a transmembrane domain, however, but is held at the cell surface by a GPI anchor via a C-terminal domain which maybe cleaved to yield a soluble form of the receptor. Multiple transcript variants encoding different isoforms have been found for this gene."
- NP_001242959.1 CD48 antigen isoform 2 precursor: "Transcript Variant: This variant (2) differs in the 3' UTR and coding region compared to variant 1. The resulting protein (isoform 2) is longer and has a distinct C-terminus compared to isoform 1." Conserved Domains (3) summary: cd05741 Location: 38  127 Ig_CEACAM_D1_like; First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins, smart00410 Location: 32  127 IG_like; Immunoglobulin like and pfam13895 Location: 148  217 Ig_2; Immunoglobulin domain.
- NP_001769.2 CD48 antigen isoform 1 precursor: "Transcript Variant: This variant (1) represents the shorter transcript and encodes the shorter protein (isoform 1)." Conserved Domains (2) summary: pfam13895 Location: 133  217 Ig_2; Immunoglobulin domain and cd05775 Location: 35  128 Ig_CD2_like_N; N-terminal immunoglobulin (Ig)-like domain of T-cell surface antigen CD2 and similar domains.
- XP_011508473.1 CD48 antigen isoform X1, Conserved Domains (3) summary: cd05741 Location: 6  95 Ig_CEACAM_D1_like; First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins, smart00410 Location: 1  95 IG_like; Immunoglobulin like and pfam13895 Location: 116  185 Ig_2; Immunoglobulin domain.
- XP_005245682.1 CD48 antigen isoform X2, Conserved Domains (2) summary: cd05741 Location: 38  127 Ig_CEACAM_D1_like; First immunoglobulin (Ig)-like domain of carcinoembryonic antigen (CEA) related cell adhesion molecule (CEACAM) and similar proteins and smart00410 Location: 32  127 IG_like; Immunoglobulin like.
Gene ID: 1048 see Carcinoembryonic antigen gene family.
Gene ID: 1088 see Carcinoembryonic antigen gene family.
Gene ID: 2324 is FLT4 fms related receptor tyrosine kinase 4 on 5q35.3: "This gene encodes a tyrosine kinase receptor for vascular endothelial growth factors C and D. The protein is thought to be involved in lymphangiogenesis and maintenance of the lymphatic endothelium. Mutations in this gene cause hereditary lymphedema type IA."
- NP_001341918.1 vascular endothelial growth factor receptor 3 isoform 3 precursor: "Transcript Variant: This variant (3) contains an alternate 3' terminal exon compared to variant 1. This results in an isoform (3) with a shorter C-terminus compared to isoform 1." Conserved Domains (6) summary: cd05862 Location: 245  329 Ig_VEGFR; Immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R), cd05863 Location: 352  418 Ig_VEGFR-3; Immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3), smart00408 Location: 693  755 IGc2; Immunoglobulin C-2 Type, smart00410 Location: 564  657 IG_like; Immunoglobulin like, and pfam13895 Location: 137  224 Ig_2; Immunoglobulin domain.
- NP_002011.2 vascular endothelial growth factor receptor 3 isoform 2 precursor: "Transcript Variant: This variant (2) contains an alternate 3' terminal exon compared to variant 1. This results in an isoform (2) with a shorter C-terminus compared to isoform 1." Conserved Domains (10) summary: cd05862 Location: 245  329 Ig1_VEGFR; First immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R), cd05863 Location: 352  418 Ig2_VEGFR-3; Second immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3), smart00408 Location: 693  755 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 564  657 IG; Immunoglobulin, smart00410 Location: 238  327 IG_like; Immunoglobulin like, pfam07679 Location: 678  765 I-set; Immunoglobulin I-set domain, pfam13895 Location: 138  224 Ig_2; Immunoglobulin domain, and cl11960 Location: 570  658 Ig; Immunoglobulin domain.
- NP_891555.2 vascular endothelial growth factor receptor 3 isoform 1 precursor: "Transcript Variant: This variant (1) encodes the longest isoform (1)." Conserved Domains (10) summary: cd05862 Location: 245  329 Ig1_VEGFR; First immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R), cd05863 Location: 352  418 Ig2_VEGFR-3; Second immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3), smart00408 Location: 693  755 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 564  657 IG; Immunoglobulin, smart00410 Location: 238  327 IG_like; Immunoglobulin like, pfam07679 Location: 678  765 I-set; Immunoglobulin I-set domain, pfam13895 Location: 138  224 Ig_2; Immunoglobulin domain and cl11960 Location: 570  658 Ig; Immunoglobulin domain.
- XP_011532780.1 vascular endothelial growth factor receptor 3 isoform X1, Conserved Domains (10) summary: cd05862 Location: 322  406 Ig1_VEGFR; First immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R), cd05863 Location: 429  495 Ig2_VEGFR-3; Second immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3), smart00408 Location: 770  832 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 641  734 IG; Immunoglobulin, smart00410 Location: 315  404 IG_like; Immunoglobulin like, pfam07679 Location: 755  842 I-set; Immunoglobulin I-set domain, pfam13895 Location: 215  301 Ig_2; Immunoglobulin domain, and cl11960 Location: 647  735 Ig; Immunoglobulin domain.
- XP_011532786.1 vascular endothelial growth factor receptor 3 isoform X6, Conserved Domains (10) summary: cd05862 Location: 92  176 Ig1_VEGFR; First immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R), cd05863 Location: 199  265 Ig2_VEGFR-3; Second immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 3 (VEGFR-3), smart00408 Location: 540  602 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 411  504 IG; Immunoglobulin, smart00410 Location: 85  174 IG_like; Immunoglobulin like, pfam07679 Location: 525  612 I-set; Immunoglobulin I-set domain, pfam13895 Location: 1  71 Ig_2; Immunoglobulin domain, and cl11960 Location: 417  505 Ig; Immunoglobulin domain.
Gene ID: 3339 is HSPG2 heparan sulfate proteoglycan 2 on 1p36.12: "This gene encodes the perlecan protein, which consists of a core protein to which three long chains of glycosaminoglycans (heparan sulfate or chondroitin sulfate) are attached. The perlecan protein is a large multidomain proteoglycan that binds to and cross-links many extracellular matrix components and cell-surface molecules. It has been shown that this protein interacts with laminin, prolargin, collagen type IV, FGFBP1, FBLN2, FGF7 and transthyretin, etc., and it plays essential roles in multiple biological activities. Perlecan is a key component of the vascular extracellular matrix, where it helps to maintain the endothelial barrier function. It is a potent inhibitor of smooth muscle cell proliferation and is thus thought to help maintain vascular homeostasis. It can also promote growth factor (e.g., FGF2) activity and thus stimulate endothelial growth and re-generation. It is a major component of basement membranes, where it is involved in the stabilization of other molecules as well as being involved with glomerular permeability to macromolecules and cell adhesion. Mutations in this gene cause Schwartz-Jampel syndrome type 1, Silverman-Handmaker type of dyssegmental dysplasia, and tardive dyskinesia. Alternative splicing of this gene results in multiple transcript variants."
- NP_001278789.1 basement membrane-specific heparan sulfate proteoglycan core protein isoform a precursor: "Transcript Variant: This variant (1) represents the longer transcript and encodes the longer isoform (a)." Conserved Domains (18) summary: cd00096 Location: 3131  3200 Ig; Immunoglobulin domainm cd05743 Location: 421  498 Ig_Perlecan_D2_like; Immunoglobulin (Ig)-like domain II (D2) of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, cd05754 Location: 1772  1857 Ig3_Perlecan_like; Third immunoglobulin (Ig)-like domain found in Perlecan and similar proteins, smart00408 Location: 1971  2033 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 414  490 IG; Immunoglobulin, smart00410 Location: 2058  2135 IG_like; Immunoglobulin like, pfam07679 Location: 3582  3659 I-set; Immunoglobulin I-set domain, pfam00047 Location: 3027  3107 ig; Immunoglobulin domain, pfam13895 Location: 2930  3010 Ig_2; Immunoglobulin domain, cl11960 Location: 3597  3652 Ig; Immunoglobulin domain.
- NP_005520.4 basement membrane-specific heparan sulfate proteoglycan core protein isoform b precursor: "Transcript Variant: This variant (2) uses an alternate in-frame splice site in the 5' coding region, compared to variant 1, resulting in an isoform (b) that is 1 aa shorter than isoform a." Conserved Domains (18) summary: cd00096 Location: 3130  3199 Ig; Immunoglobulin domain, cd05743 Location: 421  498 Ig_Perlecan_D2_like; Immunoglobulin (Ig)-like domain II (D2) of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, cd05754 Location: 1771  1856 Ig3_Perlecan_like; Third immunoglobulin (Ig)-like domain found in Perlecan and similar proteins, smart00408 Location: 1970  2032 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 414  490 IG; Immunoglobulin, smart00410 Location: 2057  2134 IG_like; Immunoglobulin like, pfam07679 Location: 3581  3658 I-set; Immunoglobulin I-set domain, pfam00047 Location: 3026  3106 ig; Immunoglobulin domain, pfam13895 Location: 2929  3009 Ig_2; Immunoglobulin domain, and cl11960 Location: 3596  3651 Ig; Immunoglobulin domain.
- XP_011539620.1 basement membrane-specific heparan sulfate proteoglycan core protein isoform X1, Conserved Domains (18) summary: cd00096 Location: 3313  3382 Ig; Immunoglobulin domain, cd05743 Location: 438  515 Ig_Perlecan_D2_like; Immunoglobulin (Ig)-like domain II (D2) of the human basement membrane heparan sulfate proteoglycan perlecan, also known as HSPG2, cd05754 Location: 1954  2039 Ig3_Perlecan_like; Third immunoglobulin (Ig)-like domain found in Perlecan and similar proteins, smart00408 Location: 2153  2215 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 431  507 IG; Immunoglobulin, smart00410 Location: 2240  2317 IG_like; Immunoglobulin like, pfam07679 Location: 3764  3841 I-set; Immunoglobulin I-set domain, pfam00047 Location: 3209  3289 ig; Immunoglobulin domain, pfam13895 Location: 3112  3192 Ig_2; Immunoglobulin domain, cl11960 Location: 3779  3834 Ig; Immunoglobulin domain.
Gene ID: 3385 see Carcinoembryonic antigen gene family.
Gene ID: 3791 is KDR kinase insert domain receptor on 4q12: "Vascular endothelial growth factor (VEGF) is a major growth factor for endothelial cells. This gene encodes one of the two receptors of the VEGF. This receptor, known as kinase insert domain receptor, is a type III receptor tyrosine kinase. It functions as the main mediator of VEGF-induced endothelial proliferation, survival, migration, tubular morphogenesis and sprouting. The signalling and trafficking of this receptor are regulated by multiple factors, including Rab GTPase, P2Y purine nucleotide receptor, integrin alphaVbeta3, T-cell protein tyrosine phosphatase, etc.. Mutations of this gene are implicated in infantile capillary hemangiomas."
- NP_002244.1  vascular endothelial growth factor receptor 2 precursor, Conserved Domains (10) summary: cd05862 Location: 239  326 Ig1_VEGFR; First immunoglobulin (Ig)-like domain of vascular endothelial growth factor (VEGF) receptor(R), cd05864 Location: 348  417 Ig2_VEGFR-2; Second immunoglobulin (Ig)-like domain of vascular endothelial growth factor receptor 2 (VEGFR-2), smart00408 Location: 680  744 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 565  661 IG; Immunoglobulin, smart00410 Location: 231  324 IG_like; Immunoglobulin like, pfam07679 Location: 667  754 I-set; Immunoglobulin I-set domain, pfam13895 Location: 551  661 Ig_2; Immunoglobulin domain, and cl11960 Location: 41  109 Ig; Immunoglobulin domain.
Gene ID: 3902 is LAG3
Gene ID: 4059 see Carcinoembryonic antigen gene family.
Gene ID: 4680 see Carcinoembryonic antigen gene family.
Gene ID: 4756 is NEO1
Gene ID: 5175 see Carcinoembryonic antigen gene family.
Gene ID: 5669 is PSG1
Gene ID: 5670 is PSG2
Gene ID: 5671 is PSG3
Gene ID: 5672 is PSG4
Gene ID: 5673 is PSG5
Gene ID: 5675 is PSG6
Gene ID: 5676 is PSG7
Gene ID: 5678 is PSG9
Gene ID: 5680 is PSG11
Gene ID: 6614 is SIGLEC1
Gene ID: 7087 see Carcinoembryonic antigen gene family.
Gene ID: 7273 is TTN titin on 2q31.2: "This gene encodes a large abundant protein of striated muscle. The product of this gene is divided into two regions, a N-terminal I-band and a C-terminal A-band. The I-band, which is the elastic part of the molecule, contains two regions of tandem immunoglobulin domains on either side of a PEVK region that is rich in proline, glutamate, valine and lysine. The A-band, which is thought to act as a protein-ruler, contains a mixture of immunoglobulin and fibronectin repeats, and possesses kinase activity. An N-terminal Z-disc region and a C-terminal M-line region bind to the Z-line and M-line of the sarcomere, respectively, so that a single titin molecule spans half the length of a sarcomere. Titin also contains binding sites for muscle associated proteins so it serves as an adhesion template for the assembly of contractile machinery in muscle cells. It has also been identified as a structural protein for chromosomes. Alternative splicing of this gene results in multiple transcript variants. Considerable variability exists in the I-band, the M-line and the Z-disc regions of titin. Variability in the I-band region contributes to the differences in elasticity of different titin isoforms and, therefore, to the differences in elasticity of different muscle types. Mutations in this gene are associated with familial hypertrophic cardiomyopathy 9, and autoantibodies to titin are produced in patients with the autoimmune disease scleroderma."
- NP_001243779.1 titin isoform N2BA: "Transcript Variant: This variant (N2BA) encodes another major cardiac isoform (N2BA). It includes the N2A and N2B exons, and also the PEVK region. This variant is supported by annotation on DNA accession AJ277892.2 and by accompanying data in PMIDs 10850961 and 11717165." Conserved Domains (16) summary: cd00096 Location: 5899  5968 Ig; Immunoglobulin domain, cd05747 Location: 33485  33576 Ig5_Titin_like; M5, fifth immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins, cd05748 Location: 21720  21791 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar proteins, smart00408 Location: 4678  4744 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 20232  20312 IG; Immunoglobulin, smart00410 Location: 28207  28289, IG_like; Immunoglobulin like, pfam07679 Location: 8888  8977 I-set; Immunoglobulin I-set domain, pfam00047 Location: 6824  6907 ig; Immunoglobulin domain, pfam13895 Location: 13398  13462 Ig_2; Immunoglobulin domain, and cl11960 Location: 24569  24642 Ig; Immunoglobulin domain.
- NP_001254479.2 titin isoform IC: "Transcript Variant: This variant (IC) represents an inferred complete model that includes all possible supported in-frame coding exons. The exons included in this inferred variant are supported by the original sequence analysis, publication data(PMID:11717165), available cDNA and EST data, and additional sequence analysis of the repetitive exons. This transcript is the longest and represents a 363-exon model encoding a predicted protein (isoform IC) of 35,991 amino acids." Conserved Domains (17) summary: cd00096 Location: 7340  7409 Ig; Immunoglobulin domain, cd05747 Location: 35126  35217 Ig5_Titin_like; M5, fifth immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins, cd05748 Location: 22567  22640 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar proteins, smart00408 Location: 4995  5061 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 21873  21953 IG; Immunoglobulin, smart00410 Location: 29848  29930 IG_like; Immunoglobulin like, pfam07679 Location: 9205  9294 I-set; Immunoglobulin I-set domain, pfam00047 Location: 7141  7224 ig; Immunoglobulin domain, pfam13895 Location: 15039  15103 Ig_2; Immunoglobulin domain, and pfam16031 Location: 12286  12406 TonB_N; TonB N-terminal region, and cl11960 Location: 26210  26283 Ig; Immunoglobulin domain.
- NP_003310.4  titin isoform N2-B: "Transcript Variant: This variant (N2-B) encodes the major cardiac muscle isoform (N2-B). It lacks multiple exons in the region encoding PEVK repeats. This results in a shortened PEVK region in isoform N2-B compared to isoform IC. This variant is supported by data in PMIDs 10850961 and 11717165." Conserved Domains (13) summary: cd00096 Location: 24053  24120 Ig; Immunoglobulin domain, cd05747 Location: 26061  26152 Ig5_Titin_like; M5, fifth immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins, cd05748 Location: 14296  14367, Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar proteins, smart00408 Location: 910  976 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 17823  17904 IG; Immunoglobulin, smart00410 Location: 20783  20865 IG_like; Immunoglobulin like, pfam07679 Location: 6  97 I-set; Immunoglobulin I-set domain, pfam13895 Location: 5974  6038 Ig_2; Immunoglobulin domain, and cl11960 Location:17145  17218 Ig; Immunoglobulin domain.
- NP_596869.4  titin isoform N2-A: "Transcript Variant: This variant (N2-A) encodes isoform N2-A, which is the predominant titin isoform in skeletal muscle. This variant lacks the N2B region but includes the PEVK region. This variant is supported by data in PMIDs 7569978, 10850961 and 11717165." Conserved Domains (16) summary: cd00096 Location: 4972  5041 Ig; Immunoglobulin domain, cd05747 Location: 32558  32649 Ig5_Titin_like; M5, fifth immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins, cd05748 Location: 19999  20072 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar proteins, smart00408 Location: 3751  3817 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 27280  27362 IG; Immunoglobulin, smart00410 Location: 19305  19385 IG_like; Immunoglobulin like, pfam07679 Location: 7961  8050 I-set; Immunoglobulin I-set domain, pfam00047 Location: 5897  5980 ig; Immunoglobulin domain, pfam13895 Location: 12471  12535 Ig_2; Immunoglobulin domain, and cl11960 Location: 23642  23715 Ig; Immunoglobulin domain.
- NP_596870.2 titin isoform novex-3: "Transcript Variant: This variant (novex-3) is the shortest transcript and encodes the shortest isoform (novex-3). Its last exon is nearly 8 kb and is not found in the other variants. The novex-3 isoform, which is found in all striated muscle, lacks the PEVK region and has a C-terminal truncation compared to longer isoforms. This variant is supported by data in PMID:11717165." Conserved Domains (6) summary: cd00096 Location: 3521  3594 Ig; Immunoglobulin domain, smart00408 Location: 956  1022 IGc2; Immunoglobulin C-2 Type, smart00410 Location: 3154  3233 IG_like; Immunoglobulin like, pfam07679 Location: 6  97 I-set; Immunoglobulin I-set domain, and cl11960 Location: 26  97 Ig; Immunoglobulin domain.
- NP_597676.3 titin isoform novex-1: "Transcript Variant: This variant (novex-1) encodes the minor cardiac muscle isoform (novex-1 or novex-1/N2B), which is nearly identical to the major cardiac isoform N2-B but contains a unique stretch of 125 aa in the I-band region. This variant is supported by data in PMID:11717165." Conserved Domains (13) summary: cd00096 Location: 24178  24245 Ig; Immunoglobulin domain, cd05747 Location: 26186  26277 Ig5_Titin_like; M5, fifth immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins, cd05748 Location: 14421  14492 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar proteins, smart00408 Location: 910  976, IGc2; Immunoglobulin C-2 Type, smart00409 Location: 16865  16945 IG; Immunoglobulin, smart00410 Location: 20908  20990 IG_like; Immunoglobulin like, pfam07679 Location: 6  97 I-set; Immunoglobulin I-set domain, cd14104 Location: 24878  25154 STKc_Titin; Catalytic domain of the Giant Serine/Threonine Kinase Titin, pfam13895 Location: 6099  6163 Ig_2; Immunoglobulin domain, and cl11960 Location: 17270  17343 Ig; Immunoglobulin domain.
- NP_597681.4 titin isoform novex-2: "Transcript Variant: This variant (novex-2) encodes the minor cardiac and skeletal muscle isoform (novex-2 or novex-2/N2B), which is nearly identical to the major cardiac isoform N2-B but contains a unique stretch of 192 aa in the I-band region. This variant is supported by data in PMID:11717165." Conserved Domains (13) summary: cd00096 Location: 24245  24312 Ig; Immunoglobulin domain, cd05747 Location: 26253  26344 Ig5_Titin_like; M5, fifth immunoglobulin (Ig)-like domain of human titin C terminus and similar proteins, cd05748 Location: 14488  14559 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar proteins, smart00408 Location: 910  976 IGc2; Immunoglobulin C-2 Type, smart00409 Location: 16932  17012 IG; Immunoglobulin, smart00410 Location: 20975  21057 IG_like; Immunoglobulin like, pfam07679 Location: 6  97 I-set; Immunoglobulin I-set domain, cd14104 Location: 24945  25221 STKc_Titin; Catalytic domain of the Giant Serine/Threonine Kinase Titin, pfam13895 Location: 6166  6230 Ig_2; Immunoglobulin domain, and cl11960 Location: 17337  17410 Ig; Immunoglobulin domain.
- XP_024308867.1 titin isoform X11, Conserved Domains (11) summary: cd05747 Location: 26091  26182 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00409 Location: 6004  6068 IG; Immunoglobulin, smart00410 Location: 4753  4823 IG_like; Immunoglobulin like, pfam07679 Location: 6  97 I-set; Immunoglobulin I-set domain, cd05748 Location: 13532  13605 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, and cl11960 Location: 21508  21581 Ig; Immunoglobulin domain, and cl28434 Location: 2079  2169 I-set; Immunoglobulin I-set domain.
- XP_024308866.1 titin isoform X9, Conserved Domains (14) summary: cd05747 Location: 32170  32261 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00060 Location: 15110  15194 FN3; Fibronectin type 3 domain, smart00409 Location: 12083  12147 IG; Immunoglobulin, smart00410 Location: 10925  10989 IG_like; Immunoglobulin like, pfam07679 Location: 8889  8978 I-set; Immunoglobulin I-set domain, cd05748 Location: 19611  19684 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, cl11960 Location: 24336  24410 Ig; Immunoglobulin domain, and cl28434 Location: 9673  9755 I-set; Immunoglobulin I-set domain.
- XP_024308865.1 titin isoform X8, Conserved Domains (13) summary: cd05747 Location: 32197  32288 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00410 Location: 12110  12174 IG_like; Immunoglobulin like, pfam07679 Location: 8889  8978 I-set; Immunoglobulin I-set domain, cd05748 Location: 19638  19711 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, cl11960 Location: 24363  24437 Ig; Immunoglobulin domain, cl28434 Location: 9673  9755 I-set; Immunoglobulin I-set domain.
- XP_024308864.1 titin isoform X6, Conserved Domains (15) summary: cd05747 Location: 33083  33174 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00409 Location: 12996  13060 IG; Immunoglobulin, smart00410 Location: 11745  11815 IG_like; Immunoglobulin like, pfam07679 Location: 8889  8978 I-set; Immunoglobulin I-set domain, cd05748 Location: 20524  20597 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, cl11960 Location: 28500  28573 Ig; Immunoglobulin domain, and cl28434 Location: 9177  9267 I-set; Immunoglobulin I-set domain.
- XP_024308862.1 titin isoform X2, Conserved Domains (15) summary: cd05747 Location: 33273  33364 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00409 Location: 13186  13250 IG; Immunoglobulin, smart00410 Location: 11935  12005 IG_like; Immunoglobulin like, pfam07679 Location: 8889  8978 I-set; Immunoglobulin I-set domain, cd05748 Location: 20714  20787 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, cl11960 Location: 28690  28763 Ig; Immunoglobulin domain, and cl28434 Location: 9177  9267 I-set; Immunoglobulin I-set domain.
- XP_024308863.1 titin isoform X3, Conserved Domains (15) summary: cd05747 Location: 33272  33363 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00409 Location: 13185  13249 IG; Immunoglobulin, smart00410 Location: 11934  12004 IG_like; Immunoglobulin like, pfam07679 Location: 8889  8978, I-set; Immunoglobulin I-set domain, cd05748 Location: 20713  20786 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, cl11960 Location: 28689  28762 Ig; Immunoglobulin domain, and cl28434 Location: 9177  9267 I-set; Immunoglobulin I-set domain.
- XP_024308868.1 titin isoform X12, Conserved Domains (13) summary: cd05747 Location: 22709  22800 Ig_Titin_like; Immunoglobulin (Ig)-like domain of human titin C terminus and similar domains, smart00409 Location: 2622  2686 IG; Immunoglobulin, smart00410 Location: 1371  1441 IG_like; Immunoglobulin like, pfam07679 Location: 20684  20771 I-set; Immunoglobulin I-set domain, cd05748 Location: 10150  10223 Ig_Titin_like; Immunoglobulin (Ig)-like domain of titin and similar domains, cl11960 Location: 13793  13866 Ig; Immunoglobulin domain, and cl28434 Location: 1814  1897 I-set; Immunoglobulin I-set domain.
Gene ID: 10892 is MALT1
Gene ID: 27036 is SIGLEC7
Gene ID: 51744 is CD244
Gene ID: 55243 is KIRREL1
Gene ID: 57611 see Immunoglobulin supergene family
Gene ID: 57863 see Carcinoembryonic antigen gene family.
Gene ID: 79368 see Immunoglobulin receptor superfamily genes.
Gene ID: 79827 is CLMP
Gene ID: 83416 see Immunoglobulin receptor superfamily genes.
Gene ID: 83417 see Immunoglobulin receptor superfamily genes.
Gene ID: 84033 is OBSCN
Gene ID: 84623 is KIRREL3
Gene ID: 84824 is FCRLA
Gene ID: 115350 see Immunoglobulin receptor superfamily genes.
Gene ID: 115352 see Immunoglobulin receptor superfamily genes.
Gene ID: 125931 see Carcinoembryonic antigen gene family.
Gene ID: 161357 is MDGA2
Gene ID: 220296 see Carcinoembryonic antigen gene family.
Gene ID: 255809 is C19orf38
Gene ID: 284021 is MILR1
Gene ID: 343413 see Immunoglobulin receptor superfamily genes.
Gene ID: 388551 see Carcinoembryonic antigen gene family.
Gene ID: 440533 is PSG8

# Hypotheses
- Downstream core promoters may work as transcription factors even as their complements or inverses.
- In addition to the DNA binding sequences listed above, the transcription factors that can open up and attach through the local epigenome need to be known and specified.
- The function of A1BG is the same as other immunoglobulin genes possessing the immunoglobulin domain cl11960 and/or any of three immunoglobulin-like domains: pfam13895, cd05751 and smart00410 in the order and nucleotide sequence: cd05751 Location: 401  493, smart00410 Location: 218  280, pfam13895 Location: 210  301 and cl11960 Location: 28  110.