Indeed, Ki‐67 expression was significantly increased in thymic lymphoma‐derived DP thymocytes in Ripk3−/−p53−/− DKO mice when compared to similar cells in Ripk3+/+ p53−/‐ mice (Figure 4D), supporting the notion of a rapid thymic tumorigenic phenotype in Ripk3−/−p53−/− DKO mice. This evidence concerns the gene MKI67 and thymus lymphoma.