Recently, many biochemical factors have been implicated in the development of MM-induced bone disease, for example, cytokines with osteoclast activating function, such as the receptor activator of nuclear factor kappa-B ligand (RANKL), macrophage colony-stimulating factor, interleukin-6 (IL-6), IL-11 and IL-1β7, which are produced or stimulated by MM–bone interaction and further stimulate osteoclast activation and proliferation, leading to increased bone resorption. The gene discussed is IL11; the disease is Miyoshi myopathy.