The orally available Btk inhibitor ibrutinib (PCI-32765) inhibited the formation of osteoclasts by regulating their differentiation, successfully inhibited RANKL-induced bone loss in mice [22], and significantly inhibited mouse multiple myeloma (MM) growth and osteolysis of implanted human bone fragments induced by MM cells [23]. Here, TNFSF11 is linked to plasma cell myeloma.