Molecular pathways such as RANK/RANKL/OPG, Notch, Wnt, RUNX2, EphrinB2/EphB4, and TNF pathway, as well as signaling molecules including DKK1, sclerostin, periostin, osteopontin, GFI1, BMPs, TGFβ, activin A, annexin II, adiponectin, BTK, SDF1a, chemokines, and interleukins, are at the spotlight of current MM research (Table 1). The gene discussed is SPP1; the disease is Miyoshi myopathy.