HLA-DRB1 and myeloid sarcoma: Interestingly, HLA-A*02:01 and HLA-DRB1*15:01 were, respectively, associated with lower and higher Epstein Barr Virus (EBV) viral load (38), broadly considered a trigger for the development of MS (39), prompting us to suggest a key role for epigenetic regulation of MHC expression in the initiation of MS.