IFNG and neoplasm: To assess the roles of IFN-γ and cytotoxicity in NK-dependent-CTLA4Ig-anti-tumor activity in vivo, the B16 melanoma mice treated with either CTLA4Ig or control IgG were sacrificed 10 days after tumor inoculation; magnetic-activated cell sorting (MACS, Miltenyi Biotec) was used to isolate the infiltrating NK cells from lung tissue for the analysis of cytolytic activity and cytokine production.