Chimeric antigen receptor (CAR) T-cell therapy is a type of adoptive cell transfer therapy where T cells are engineered to target tumor antigens expressed on the membrane of cancer cells. CARs are hybrid (i.e., chimeric) receptors formed by the fusion of 3 parts: an extracellular tumor-specific antibody, a transmembrane portion and an intracellular portion that stimulates T-cell activity when the antigen binds the extracellular antibody. CAR T-cell therapy is not dependent on MHC neoantigen presentation and thus can be effective when MHC molecules have been downregulated by a tumor.