For example, CAR T-cell therapy for multiple myeloma targeting B-cell maturation antigen (BCMA) can be improved by simultaneous targeting of an additional antigen, e.g., G protein-coupled receptor class-C group-5 member-D (GPRC5D), to prevent BCMA escape-mediated relapse [1]. Here, TNFRSF17 is linked to plasma cell myeloma.