HLA-DPB1 and myeloid sarcoma: Thus, the researchers concluded that in MS, the associations with HLA-DP and HLA-DR are independent of each other, but the combined presence of HLA-DPw4 (cellularly defined) and HLA-DR2 represented a significantly higher risk than either antigen alone, indicating that synergism between HLA-DP and HLA-DR gene products may play a role in the genetic susceptibility to MS.