In multiple myeloma-derived BMMSCs, it has recently been reported that miR-21 directly targeted to reduce OPG and indirectly promoted RANKL by targeting the signal transducer and activator of transcription 3 (STAT3) pathway, suggesting inhibition of osteoclastogenesis by miR-2110. The gene discussed is TNFRSF11B; the disease is AL amyloidosis.