CKLF-like MARVEL transmembrane domain-containing family
The CKLF-like MARVEL transmembrane domain-containing family (CMTM), previously termed the chemokine-like factor superfamily (CKLFSF), consists of 9 proteins, some of which have various isoforms due to alternative splicing of their respective genes. These proteins along with their isoforms are: All of these proteins have domains (i.e. regions) similar to analogous domains in the chemokine proteins; tetraspanin proteins (also termed transmembrane-4 superfamily proteins); myelin and lymphocyte protein (also termed MAR protein); proteins that direct membrane vesicle trafficking; and other proteins that are embedded in cell membranes. The genes encoding (i.e. directing  the production of) these proteins, "CKLF, CMTM1, CMTM2, CMTM3, CMTM4, CMTM5, CMTM6, CMTM7," and "CMTM8", respectively, also share similar regions that encode the domains just cited for their proteins. (The 8 CMTM genes were formerly termed CKLFSF1, CKLFSF2, CKLFSF3, CKLFSF4, CKLFSF5, CKLFSF6, CKLFSF7, and CKLFSF8.) The "CKLF, CMTM1, CMTM2, CTMT3," and "CMTM4" genes cluster together in band 22 on the long (i.e. "q") arm of chromosome 16; the "CMTM6, CMTM7," and "CMTM8" genes form a second cluster in band 22 on the short (i.e. "p") of chromosome 3; and the "CMTM5" gene, located in band 11.2 on the q arm  of chromosome 14, is not clustered with the other CMTM genes. These structural similarities and clusterings reflect the close relationships of these proteins and genes. Studies suggest that the members of this family may be involved in the development of various cancers autoimmune diseases, cardiovascular diseases, the male reproductive system, and angiogenesis (i.e. development of new blood vessels from pre-existing blood vessels). In most of these cases, however, further studies are needed to determine if these CMTM proteins and/or their corresponding genes and mRNAs will be promising targets to help in the diagnosis, prognosis, and/or treatment of these disorders