The above interactions are mediated by secretion of multiple cytokines, including interleukin-6 (IL-6), insulin-like growth factor-1 (IGF-1), IL-1, tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), Dickkopf-related protein 1 (DKK1) and secreted frizzled-related protein (sFRP), that support paracrine interactions between MM cells and endothelial cells, bone marrow stromal cells (BMSC), osteoblasts, osteoclasts and immune cells. Here, DKK1 is linked to Miyoshi myopathy.