The frequent and conserved DR3-B8-A1 extended haplotype confers less diabetes risk than other DR3 haplotypes.
Baschal EE, Aly TA, Jasinski JM, Steck AK, Johnson KN, Noble JA, Erlich HA, Eisenbarth GS. The frequent and conserved DR3-B8-A1 extended haplotype confers less diabetes risk than other DR3 haplotypes. Diabetes Obes Metab. 2009 Feb; 11 Suppl 1:25-30.