HLA-B and AIDS: HLA-B35 subtypes, such as HLA-B*35:02 and B*35:03, which have the peptide binding motif of proline at P2 and a nontyrosine residue at the C terminus, referred to as HLA-B*35-PX, have a significant association with the rapid AIDS progression in Caucasians, whereas other subtypes with the motif proline at P2 and tyrosine at the C terminus (HLA-B*35-PY) do not (27, 28).