To determine which FcγR-expressing effector cell types are involved in the antibody mediated tumor protection induced by MCMV-TRP2 vaccination, the outgrowth of B16 cells was monitored after s.c. transplantation, followed two days later by depletion of the following cell types: macrophages (depleted by clodronate liposomes), neutrophils (depleted by anti-Ly6G antibody) and NK cells (depleted by anti-NK1.1 antibody). The gene discussed is FCGR2A; the disease is neoplasm.