We found that the pulmonary arterial hypertension-enriched C allele of rs2856830 was associated with HLA-DPB1*02:01/02:02/16:01 (all p<1 × 10–9 after false discovery rate correction; table 2; appendix p 19), which all contain the Glu69 residue. The gene discussed is HLA-DPB1; the disease is pulmonary arterial hypertension.