- The cytotoxic T cell response to the male-specific histocompatibility antigen (H-Y) is controlled by two dominant immune response genes, one in the MHC, the other in the Tar alpha-locus. Epstein, R., Sham, G., Womack, J., Yagüe, J., Palmer, E., Cohn, M. J. Exp. Med. (1986)