We also looked at CD45 immunofluorescence staining of femur and vertebral bone marrow, which showed dense CD45+ hematopoietic infiltrates in control mice but a near-complete absence of CD45+ cells in the 18.5 MBq [131I]I-BCMA-Nb-treated group, consistent with effective depletion of BCMA-expressing myeloma cells from the marrow (Supplemental Fig. S13). Here, TNFRSF17 is linked to plasma cell myeloma.