HLA-DRB1 and myeloid sarcoma: Indeed, genetic associations of HLA class II (HLA-DRB1*15) and HLA class I (HLA-A*02, -A*03, and -B*07) with MS, as well as the presence of autoreactive CD4+ and CD8+ T lymphocytes, together with other inflammatory cells and cytokines in active MS lesions, suggest an autoimmune pathogenesis [5, 6].