It has been newly reported that IR increased PD-L1 expression and decreased expression of NKG2DL in radioresistant malignant cells, protecting tumor cells from NK cell cytotoxicity through the IL-6-the mitogen-activated protein kinase (MEK)/ERK pathway, which could be abrogated with the combination of PD-L1 Ab and MEK/ERK inhibitor (126). The gene discussed is CD274; the disease is neoplasm.