CTLA4 and cancer: Various receptors, such as CD19, CD2, CD20, CD22, CD33, CD123, CD138, CD171, HER2, PD-1, E7, CTLA-4, Igκ, glypican 3, LewisY antigen, fibroblast activation protein α (FAP-α), ROR1, protein claudin-6 (CLDN6), EGFRvIII, BCMA, IL-13Rα, MUC-1, GD2, CEA, VEGR, ICAM-1 and prostate-specific membrane antigen (PSMA) have been identified as targets for CAR T cells in multiple types of cancers [332, 334–338].