Fig. 1

Bone marrow core biopsy and cell samples obtained before and after anti-BCMA CAR-T cells infusion a Hematoxylin and eosin staining, Immunohistochemical (IHC) staining for CD138 and BCMA. Bone marrow cells were 3% plasma cells as shown by CD138 staining at 7 days before the anti-BCMA CAR-T cells infusion. BCMA expression was uniform on the CD138 positive plasma cells (original magnification, × 400). b No plasma cells on hematoxylin and eosin staining, CD138, and BCMA immunostaining on day 60 after anti-BCMA CAR-T cells infusion (original magnification, × 400). c Flow cytometry showed uniform BCMA expression on CD38-positive malignant plasma cells before the anti-BCMA CAR-T cells infusion. d No plasma cells in the bone marrow cells on day 60 after anti-BCMA CAR-T cells infusion