In an attempt to maximize the anti-cancer capacity of GvL effects that could be induced by MHC-compatible donor lymphocytes we used our spontaneous murine B cell leukemia (BCL1) (Slavin and Strober 1978) first documenting that even the GvL-like effects induced by syngeneic donor lymphocytes could be amplified by activation with interleukin 2 (IL-2) (Slavin et al. 1988; Ackerstein 1991). The gene discussed is IL2; the disease is cancer.