The down-regulation of immune-checkpoint receptors (PD1, CTLA4, TIGIT, etc.), up-regulation of cytokines (IFN-γ, TNF-α, IL2), and activation of granzyme and perforin, etc., remained the primary readouts to characterize the antitumor potential of tumor-infiltrated and activated T-cells56. The gene discussed is PRF1; the disease is neoplasm.