CD19 and plasma cell myeloma: With ongoing attempts to target additional markers of malignancies and to even apply CAR technology to solid tumors, the most prevalent targets in addition to CD19 are the less abundantly expressed CD22 and CD20 for B cell malignancies [38,39] and the B cell maturation antigen (BCMA; by idecabtagene vicleucel/Abecma®) for multiple myeloma [40].