The situation is reminiscent of type 1 diabetes, where amino acids at residue 57 of the HLA-DQ β chain associated with disease risk contribute to a larger volume of pocket P9 and a positive charge, allowing, e.g., glutamate residues from insulin peptides at position 9.30 In HLA-DR, Asn37 would restrict the range of amino acids at anchor position 9 of the peptide, and thereby which peptides may be presented. The gene discussed is INS; the disease is type 1 diabetes mellitus.