This allows the CAR to recognize extracellular antigens, which, in the case of multiple myeloma, is mainly the B-cell maturation antigen (BCMA); however, multiple myeloma cells express on their surfaces a multitude of other antigens (GPCR5, CD38, FcRH5, etc.)that can be targeted by specific CARs. The gene discussed is FCRL5; the disease is AL amyloidosis.