The results showed that tumor-infiltrating NK cells from mice treated with CTLA4Ig possessed significantly higher cytolytic activity than those treated with control IgG (Figure 3A, from 44.2±4.2% vs 60.7±4.3%, p=0.007), but there were no significant differences in IFNγ and TNFα production in NK cells between the CTLA4Ig group and control IgG group (Figure 3B). This evidence concerns the gene IFNG and neoplasm.