Several studies reports that post mortem brain and spinal tissue from MS patients contain increased levels of COX‐2 in association with microglia, macrophages and oligodendrocytes.36 COX‐2 leads to proinflammatory eicosanoids, and stimulates cytokine production and activation of microglia and astrocytes, thereby contributing to MS pathology.37, 38 Arg‐1, a cytosolic enzyme, is important in the repair of damaged tissue by generating putrescine that has pro‐repair properties. The gene discussed is ARG1; the disease is myeloid sarcoma.