Therefore, the tumor-site-specific activation of the PD-1/PD-L1 pathway is determined by localized induction of PD-L1 by IFNG, which indicates that higher CTL releasing IFNG and higher expression of PD-L1 are signs of impaired antitumor immune response caused by dysfunctional T-cells [22]. Here, PDCD1 is linked to neoplasm.