CD4 and leukemia: Thus, transferring αβ TCRs into γδ T cells generate potent effector T cells for leukemia immunotherapy without expressing a potentially hazardous mix of TCR dimers [36]; (2) transduction of a pan-cancer reactive γδ TCR with CRISPR/Cas9 knockout of endogenous αβ TCRs in CD4+ and CD8+ T cells resulted in more efficient TCR-T cells against a panel of leukemia [35]; (3) introduction of TCRαβ genes into hematopoietic stem cells (HSCs) that could be further promoted to differentiate into specific T cells in vivo [37]; and (4) TCR-T cells derived from reprogrammed T cells [38] (Table 2).