XRCC6 and lymphoma: Previous reports also show that cell cycle arrest, including cellular senescence, plays a greater role than apoptosis to suppress tumorigenesis in NHEJ-deficient mice.49, 50 Consistent with these findings, this study shows extended survival in male and female ku70−/−bax+/− mice and male ku70−/−bax−/− mice without a significant increase in the incidence of lymphoma (Supplementary Table S1).