And a slightly more γ-H2AX and H2Bub1 were still present in these USP22−/− H1299 cancer cells at 48 h post-irradition (Fig. 6c-d, right panel), indicating USP22 knockout impaired deubiquitination of H2Bub1 that may be required for prompt and correct DSB repair. Here, H2AX is linked to cancer.