To evaluate differences in phenotype and efficacy between HD-derived and multiple myeloma–derived CAR T cells, a second-generation fully human anti-BCMA CAR construct (ref. 28; Fig. 2A) was used to generate anti-BCMA CAR T cells from HDs and patients with multiple myeloma, subcategorized into newly diagnosed (ND), early relapsed and late relapsed multiple myeloma patients. The gene discussed is TNFRSF17; the disease is AL amyloidosis.