Testing in the ELISPOT assay the ability of spleen T cells to produce IFN-γ upon the TRP-2 peptide vaccination, we found that both wild type and tumor free transgenic animals displayed comparable amounts of IFN-γ-secreting T cells (Figure 5b,c), which was much lower than those in the same mouse groups after the immunization with OVA peptide (Figure 4b,c). This evidence concerns the gene IFNG and neoplasm.