The analysis was then repeated using 812 European IPAH cases and significant associations were observed for BMPR2, KLK1 and GGCX. GGCX encodes γ-glutamyl carboxylase and has previously been implicated in coagulation factor deficiencies and vascular calcification [203], but again, never in PAH. This evidence concerns the gene GGCX and idiopathic pulmonary arterial hypertension.