Later, it was identified that the population of plasma microparticles that were increased in MS were derived from endothelial cells and in vitro experiments demonstrated that endothelial cells activated with tumor necrosis factor-alpha (TNF-α) released microparticles that bound, activated and enhanced the transmigration of monocytes across an endothelial cell layer [15]. The gene discussed is TNF; the disease is myeloid sarcoma.