Thus, it is likely that PD-L1 overexpression on tumor cells resulted from the release of driving cytokines secreted from the TILs in the tumor microenvironment, indicating that immunotherapies aimed with checkpoint blockade or signal disengagement might be of extraordinary efficacy in tumors with abundant TIL infiltration during the negative feedback stage of smoldering immune response, despite the complexity and dynamics of immune regulation networks in vivo [37]. Here, CD274 is linked to neoplasm.