The equally efficacious anti-tumor activity of the IL-7/15 and IL-7/15/21 lymphocytes in vivo, despite lower effector function, is in agreement with findings of other authors who suggest that T cells with greater cytotoxicity or IFN-γ release may be less effective at inducing tumor regression than memory T cells [17,18,30]. The gene discussed is IL7; the disease is neoplasm.