HLA-DRB1 and myeloid sarcoma: However, EBV infection alone was significantly associated with MS (OR, 2.60; 95%CI, 1.48–4.59) (Fig. 2a), and HLA-DRB1*1501 significantly increased the risk of MS (OR, 3.06; 95%CI, 2.30–4.08) (Fig. 2b).