Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

[EX Q]: Context: The failure of in utero transplantation in immune-competent recipients suggests the existence of a fetal immune barrier. The importance of donor major histocompatibility complex (MHC) class I expression in the induction of prenatal tolerance remains undefined. We hypothesized that donor cell MHC class I expression facilitates engraftment in prenatal allogeneic recipients rather than promoting immune rejection.', 'B6.Ly5.2 (class I(+)) or B6.TAP(-/-) (class I(-)) murine fetal liver cells were transplanted into age-matched allogeneic fetal recipients. Survival to weaning and subsequent growth was assessed. Engraftment rates and peripheral blood chimerism levels were measured serially.', 'The presence or absence of class I expression did not affect survival or growth of recipients and no graft-vs-host disease developed. Allogeneic recipients of B6.Ly5.2 cells exhibited significantly higher levels of donor hematopoietic chimerism when compared to recipients of B6.TAP(-/-) cells (27% + 10% vs 11% + 8%; P = .004) that deteriorated further over time.
Answer: Donor class I MHC antigen expression is essential for stable long-term engraftment and maintenance of donor-specific tolerance. Further studies are needed to better characterize the role of the fetal innate immune system in prenatal allotransplantation.
[EX A]: Does donor major histocompatibility complex class I expression determine the outcome of prenatal transplantation?

[EX Q]: Context: To describe the common locations of active trigger points (TrPs) in the temporalis muscle and their referred pain patterns in chronic tension type headache (CTTH), and to determine if pressure sensitivity maps of this muscle can be used to describe the spatial distribution of active TrPs.', 'Forty women with CTTH were included. An electronic pressure algometer was used to assess pressure pain thresholds (PPT) from 9 points over each temporalis muscle: 3 points in the anterior, medial and posterior part, respectively. Both muscles were examined for the presence of active TrPs over each of the 9 points. The referred pain pattern of each active TrP was assessed.', 'Two-way analysis of variance detected significant differences in mean PPT levels between the measurement points (F=30.3; P<0.001), but not between sides (F=2.1; P=0.2). PPT scores decreased from the posterior to the anterior column (P<0.001). No differences were found in the number of active TrPs (F=0.3; P=0.9) between the dominant side the nondominant side. Significant differences were found in the distribution of the active TrPs (chi2=12.2; P<0.001): active TrPs were mostly found in the anterior column and in the middle of the muscle belly. The analysis of variance did not detect significant differences in the referred pain pattern between active TrPs (F=1.1, P=0.4). The topographical pressure pain sensitivity maps showed the distinct distribution of the TrPs indicated by locations with low PPTs.
Answer: Multiple active TrPs in the temporalis muscle were found, particularly in the anterior column and in the middle of the muscle belly. Bilateral posterior to anterior decreased distribution of PPTs in the temporalis muscle in women with CTTH was found. The locations of active TrPs in the temporalis muscle corresponded well to the muscle areas with lower PPT, supporting the relationship between multiple active muscle TrPs and topographical pressure sensitivity maps in the temporalis muscle in women with CTTH.
[EX A]: Are multiple active myofascial trigger points and pressure pain sensitivity maps in the temporalis muscle related in women with chronic tension type headache?

[EX Q]: Context: Genetic variants in DLG5, which encodes a scaffolding protein on chromosome 10q23, and tumor necrosis factor (TNF)-alpha, encoding a proinflammatory cytokine on chromosome 6p, have recently been reported to be associated with inflammatory bowel disease (IBD). We studied these variants to seek evidence of association with IBD in a large independent dataset.', "We genotyped 1104 unrelated white IBD subjects-496 with Crohn's disease, 512 with ulcerative colitis, and 96 with indeterminate colitis from the Cambridge/Eastern (UK) panel-and 760 healthy control subjects for DLG5_113G/A, DLG5_4136C/A, TNF-857C/T, and TNF-1031T/C polymorphisms. Known Crohn's disease-predisposing variants in CARD15/NOD2 were also genotyped to permit analysis for reported epistatic interactions.", ": TNF-857 was shown to be associated with IBD overall (P = 0.0079). A formal interaction test showed that TNF-857 is associated equally with ulcerative colitis and Crohn's disease. Neither of the DLG5 alleles, however, was associated with IBD (P = 0.32 and 0.35). Subgroup analysis also failed to show evidence of association between either DLG5 allele or genotype frequencies and ulcerative colitis or Crohn's disease. Stratification of TNF-alpha and DLG5 cases by CARD15 genotype made no significant difference in the strength of associations.
Answer: We have confirmed an association between the TNF-857 promoter polymorphism and IBD in a large independent UK dataset but were unable to replicate an association at the previously reported loci within DLG5. This may reflect heterogeneity between the populations, a smaller effect size than originally predicted, or possibly a false-positive result in the original study. Further fine mapping studies of the TNF promoter region and studies assessing functional consequences of TNF promoter polymorphisms are now required in IBD.
[EX A]:
Are genetic variants in TNF-alpha but not DLG5 associated with inflammatory bowel disease in a large United Kingdom cohort?