The risk alleles at both signals within the SOX17 locus are common (risk allele frequencies are 74% for rs13266183-C and 92% for rs9298503-C), such that 1230 (59%) of 2085 patients with pulmonary arterial hypertension were homozygous for the risk allele at both SOX17 SNPs, compared with 4443 (46%) of 9659 controls. The gene discussed is SOX17; the disease is pulmonary arterial hypertension.