CYP27B1 and myeloid sarcoma: Multiple sclerosis (MS), a demyelinating disease of the central nervous system (CNS), is considered to be an inflammatory disease of autoimmune origin.[1] A low vitamin D status, measured as 25(OH)D, has been associated with an increased risk of developing MS [2, 3] and vitamin D related genes, such as CYP24A1 and CYP27B1 emerge from gene wide association studies.[4]