HLA-DRB1 and myeloid sarcoma: MBP-specific CD4+ T cells have beenrevealed in the brain and spinal cord tissues of MS patients[40], while APCs presenting the mainencephalitogenic peptide MBP (a fragment consisting of amino acids 85–99)have been detected directly in demyelination foci[41, 42].MHC II molecules encoded by HLA-DRB1*1501, the universal risk allelefor MS that binds to the MBP85-99 fragment, play a crucial role in thepresentation of this peptide on the surface of APCs.