The proliferation of MM cells is triggered by cytokines such as IL-6, IGF-1, VEGF, TNF-α, stromal cell derived factor-1α (SDF-1α), and IL-21 and is mediated through the RAF/mitogen-activated protein kinase kinase (MEK)/p42/p44/mitogen-activated protein kinase (MAPK) signaling cascade [27, 30, 32, 36–39]. The gene discussed is CXCL12; the disease is Miyoshi myopathy.