When the logistic regression model for benign MS was used to adjust for the same confounding factors as MSSS, living at a higher latitude and carrying the HLA-DRB1*04:05 allele were significantly associated with benign MS (adjusted OR = 2.63, p = 0.0206; adjusted OR = 2.49, p = 0.0275, respectively), while SPMS had a negative association (p < 0.0001). Here, HLA-DRB1 is linked to myeloid sarcoma.