GYPC and pulmonary arterial hypertension: Childhood exposure to the PAH cluster was associated with six CpG sites at P < 1.20 × 10, four of which were hypomethylated (cg04320476, cg12564034, and cg15090217, all annotated to SLC43A2, and cg17105014, annotated to GYPC), while two were hypermethylated (cg19326543, LIMS2 and cg23109721).