Similarly, using RP9 cells expressing chicken MHC class I glycoproteins complexed with ALV antigens, Thacker et al. (1995) detected antigen-specific, MHC-restricted CD8+CTLs in peripheral blood of ALV-inoculated chickens and found that the difference in cytolytic activity to Rous sarcoma virus (RSV)-induced tumors between B21 and B13 chicken line was associated with their resistance to the tumor development. Here, CD8A is linked to neoplasm.