MM cells also express multiple cytokines and chemokines, such as interleukin (IL)-3, IL-7, monocyte chemotactic protein (MCP)-1, macrophage inflammatory protein (MIP)-1α, and parathyroid hormone-related protein (PTHrP), all of which enhance OC differentiation and activity in a RANKL-dependent or -independent manner[18]. Here, PTHLH is linked to Miyoshi myopathy.