XRCC4 and neoplasm: Interestingly, many of these genes are known to be involved in cell-cycle function (CDK2, CDK6, CCNB1, CEP55, CENPF), transcriptional regulation/tumor suppression (FOXO3, TOP2A), DNA-damage response (ASPM, XRCC4), and tumor progression (CYR61, MACC1, CXCR4).