We therefore used CRISPR/Cas9 gene editing to knock out the TRAC gene50 in CLL1CART (CD8α H + TM, 4-1BB co-stim) and tested their in vivo anti-leukemia activity against a bioluminescent U937 cell line xenograft model to assess whether the suspected TCR-mediated alloreactivity was specific to primary cells. The gene discussed is TRAC; the disease is leukemia.