HLA-DRB1 and myeloid sarcoma: After adjusting for factors contributing to MSSS, namely geographic region (northern vs. southern), sex, age at onset, MS subtype, ARR, HLA-DRB1*04:05, and HLA-DRB1*15:01, patients living at a higher latitude and with the HLA-DRB1*04:05 allele were independently associated with the lowest quartile of MSSS (adjusted OR = 3.64, p < 0.0001 and adjusted OR = 1.81, p = 0.0266, respectively).