When examined by CIBERSORT analysis through the TIMER2.0 web server (259, 260), the mRNA levels of many DDR factors, such as RPA1, Ku70, Ku80, MRE11A, RAD50, NBS1, PRKDC, RAD51, PARG and XRCC4, were negatively associated with cytotoxic CD8+ T cells infiltration levels across various cancer types (Figure 3A). This evidence concerns the gene PRKDC and cancer.