TNFRSF17 and AL amyloidosis: The use of B cell maturation antigen (BCMA), a member of the tumor necrosis factor superfamily that is widely expressed on the surface of multiple myeloma cells but has limited expression on normal human cells and no expression on hematopoietic cells, might be the key breakthrough, as suggested by multiple clinical trials using BCMA-targeting CAR-T therapy (39–41).