CD4 and neoplasm: The Tcrβ, Tcrα, and Igh gene loci were most frequently rearranged with Tcrα rearrangements detected in all four tumor samples (Figure S2A; Table S2), indicating that p53−/− T cell tumor clone(s) originate from a cluster of differentiation 4 (CD4)+/CD8+ double positive (DP) and/or single positive (SP) T cell stage (Figure 1A).