XRCC4 and malignant colon neoplasm: Consistent with the Oncomine gene expression analysis, total protein levels of Ku70 (XRCC6), Ku80 (XRCC5), DNA-PKcs (PRKDC), XRCC4, and PAXX were found to be significantly higher in colon cancer tissue compared to normal colon tissues, while LIG4, which exhibited reduced mRNA expression in Oncomine analysis, also displayed higher total protein levels in tumors (p < 0.01 for all, Figures 2A–G).