Although monocytes/macrophages are thought to primarily have detrimental effects on MS pathogenesis and development, other studies point toward a dual role for these cells since it has been proven that they can also contribute to the clearance of tissue debris and promote tissue repair by secreting growth factors and anti-inflammatory cytokines, such as nerve growth factor (NGF) and interleukin (IL)-10 [14–16]. The gene discussed is NGF; the disease is myeloid sarcoma.