We confirmed YS- and P-Sp-derived DN3 cells engrafted in the recipient thymus, and transplanted NICD-expressing cells included CCR9+DN3 cells, in line with the previous report that DN3 contains self-renewing leukemic cells in a T-ALL mouse model (Tremblay et al., 2010; Gerby et al., 2014). The gene discussed is CCR9; the disease is acute lymphoblastic leukemia.