CTL analysis of NSG-HLA-A24/HHD WT1-TCR gene–transduced HSC recipients. (A) Representative flow cytometry plots showing tetramer analysis in the spleen (left 2 plots) and thymus (right 2 plots) of recipients transplanted with WT1-TCR gene–transduced HSCs. (B) The frequencies of WT1-specific CTLs in spleen were significantly increased in the recipients of WT1-TCR gene–transduced HSCs compared with those of nontransduced or control vector–transduced HSCs. The frequencies of WT1 tetramer⁺ gated on CD8⁺ T cells (%) are shown for spleen (left), thymus (center), and BM (right). Spleen: n = 6 nontransduced or GFP control vector–transduced HSC recipients, 0.027% ± 0.010%; n = 9 WT1-TCR gene–transduced HSC recipients, 0.316% ± 0.070%, **P = .0055; thymus: n = 5 nontransduced or GFP control vector–transduced HSC recipients, 0.074% ± 0.031%; n = 11 WT1-TCR gene–transduced HSC recipients, 1.158% ± 0.513%; and BM: n = 3 nontransduced or GFP control vector–transduced HSC recipients, 0.093% ± 0.041%; n = 3 WT1-TCR gene–transduced HSC recipients, 0.565% ± 0.200%. tet, tetramer.