In MS, AP-1 and NF-κB are activated [33] and specific enzymes and their products involved in inflammation are overexpressed: matrix metalloproteinase-9 (MMP-9, gelatinase B), plasminogen activators, phospholipase A2 (PLA2), cyclooxigenase-2 (COX-2) and prostaglandins, lipoxygenases (LOX) and leukotrienes, Th1 cytokines, IL-1 and TNF, adhesion molecules, reactive oxygen species (ROS), as well as nitric oxide synthase (NOS) and nitric oxide. The gene discussed is MMP9; the disease is myeloid sarcoma.