HLA-C and acute lymphoblastic leukemia: The purpose of CAR-T in B-ALL is to enable tumor-associated antigen recognition of T cells regardless of MHC, and the mechanism is to develop a CAR construct, which contains scFv extracellularly (for antigen binding), transmembrane domain (for receptor stabilization), and CD3ζ signaling domain intracellularly (for T cell stimulation)23.