HLA-DRB1 and myeloid sarcoma: Pertaining to the HLA class II results, the high frequencies of HLA-DRB1*03 (19.2%), DRB1*13 (15.8%), DRB1*07 (14.86%), and DRB1*04 (12.7%) found in our study are also described as susceptibility factors of MS in several groups within different ethnic backgrounds, notably Arabs [5,6].