IL10 and acute lymphoblastic leukemia: We also detected the level of IL-10 in the supernatant following CAR-T cells cocultured with tumor cells and found that the level of IL-10 was higher in the PB (patient) CAR-T group than those in the CB and PB CAR-T groups, which further demonstrates that autologous CAR-T cells in R/R ALL patients have higher Treg levels and could secrete IL-10, which inhibited antitumor effects.