IFNG and neoplasm: Some reports show that CD4+ T-cells can differentiate into cytotoxic cells expressing granzymes and Fas Ligand and directly kill tumor cells expressing MHC-II.41–44 To ascertain the role of CD4+ T-cells in the direct targeting of MHC-II-positive PDAC cells, we co-cultured purified activated CD4+ T-cells with IFN-γ-stimulated PDAC cells overnight and assessed cytotoxicity.