XRCC5 and lymphoma: Also, the rapid development of lymphoma in Lig IV−/−p53−/−, XRCC4−/−p53−/−, Ku80−/−p53−/−, and DNA-PKcs−/−p53−/− mice supports the notion that lymphomagenesis is increased by NHEJ loss, especially if the p53 activity is impaired [96].