H2AB1 and tuberculosis: Analogously, the presence of the H2b-encoded aspartic acid in the H2-Ab1 of the B6.I-100 strain is unlikely to influence the level of TB susceptibility, since B6-I.100 mice display a phenotype identical to that of B6.I-249.1.15.46 mice, whose entire H2-Ab1 gene was inherited from I/St mice.