Though conventionally exploited for its ability to effect DNA damage and cell death (6), recently RT has been found to produce a host of immunomodulatory effects on tumors through altering the tumor microenvironment (7, 8), initiating immunogenic cell death (9, 10), and altering the surface expression of immune markers, such as major histocompatibility complex (MHC) molecules and PD-L1, on cancer cells (11–14). This evidence concerns the gene CD274 and cancer.