In a recent study conducted by Bove et al. which included the major genetic risk factor of MS (HLA-DRB1*1501), the risk allele carriers showed an earlier age at onset (as expected), and each 1-year later age at menarche was also associated with later age at onset after adjusting for multiple potential confounders (increased by 0.63 years, P=0.033), consistent with previous findings. This evidence concerns the gene HLA-DRB1 and myeloid sarcoma.