Given that CYP24A1 encodes the enzyme responsible for initiating the degradation of 1,25-dihydroxyvitamin D3 (the physiologically active form of vitamin D3) we suggest that the observation of an eQTL provides genetic evidence for a pathogenic role for low levels of 1,25-dihydroxyvitamin D3 in MS. The gene discussed is CYP24A1; the disease is myeloid sarcoma.