TNFRSF17 and plasma cell myeloma: To test the activity of CS1-CAR-T cells and CS1-BCMA CAR-T cells in vivo, NSG mice were intravenously injected with 2 × 106 MM1S multiple myeloma cells, followed the next day by 1 × 107 frozen T cells or monospecific CS1, monospecific BCMA, or bispecific CS1-BCMA CAR-T cells via the same route.