The in vitro and in vivo antitumor effect of anti-BCMA-Exo-Btz in MM. (A) Cell viability of MM cells in response to treatment with free Btz, CL-Exo, and CL-anti-BCMA-Exo-Btz. (B-C) In situ myeloma models were constructed by injecting LP-1 cells in the tail vein of NSG mice and measured once every 3 days after treatment. The fluorescence intensity (B) and tumor growth curve (C) of the mice are shown. (D) Kaplan-Meier analysis revealed describe the survival rate of the mice in experiment. ∗P < .05; ∗∗P < .01; ∗∗∗P < .001; ∗∗∗∗P < .0001.