In contrast, we did not detect V(D)J rearrangements or CD28/TCRβ expression in Rag2−/−p53−/− lymphomas owing to the incapacity of developing T cells to initiate V(D)J recombination and differentiate in the absence of RAGs (Figures S2A and S2B; Table S2) (Shinkai et al., 1992). Here, CD28 is linked to lymphoma.