The use of CAR T cells enriched for TCM and TSCM has reached the clinic even in solid tumors: the GD2-CD28-OX40 CAR manufactured in IL-7/IL-15 (157) is currently in a phase I trial to treat patients with sarcoma, osteosarcoma, neuroblastoma, and melanoma (NCT02107963). Here, CD28 is linked to neuroblastoma.