IFNG and neoplasm: The anti-E7 T-cell responses were first analyzed by IFN-γ ELISpot assays, using splenocytes collected seven days after the second immunization and stimulated ex vivo with the HPV16 E7(11-19) peptide (YMLDLQPET, containing an HLA-A2.1-restricted epitope)43, the HPV16 E7-expressing syngeneic tumor cell line PAP-A244 or HPV18 E7(7-15) peptide (TLQDIVLHL, containing an HLA-A2.1-restricted epitope)45, respectively.