B5 and B15 associated with progressive Marek's disease, Rous sarcoma, and avian leukosis virus-induced tumors in inbred 15I4 chickens.

RPRL 15I4 inbred chickens are nearly histocompatible except for the B5 and B15 haplotypes that determine the major transplantation antigens. B5B5 and B15B15 15I4 chickens were equally and highly susceptible to tumors induced by Marek's disease, Rous sarcoma, or avian leukosis viruses (ALV), suggesting both of these haplotypes may determine a general influence leading to tumor development. The 15I4 birds were highly susceptible to erythroblastosis, and most developed immunological tolerance to the virus after ALV infection.