IFNG and neoplasm: On the one hand, IFN-γ from lymphocytes induces PD-L1 expression, suppressing the effector of tumor-specific T cells or NK cells and favoring cancer cell immune evasion and progression [52–55]; on the other hand, IFN-γ + Tregs are epitope-specific Tregs that suppress the proliferation of cognate epitope-specific effector cells, and the suppression was 20–50-fold greater if Tregs were specific for an epitope [56].