Macrophages are central cells that are also involved in MS progression, along with other cells and molecules, such as activated T cells (secretors of interleukins), microglial cells, astrocytes, and molecules that mediate inflammation: anti-myelin antibodies, tumor necrosis factor alpha (TNF-α), interferon gamma (IFN-γ), and serum complement. This evidence concerns the gene TNF and myeloid sarcoma.