The PAH biomarker genes selected for analysis by qPCR were Cytochrome P450 Family 1 Subfamily A Member 1 (CYP1A1) and Cytochrome P450 Family 1 Subfamily B Member 1 (CYP1B1) shown in Figures 3A,B. Here, CYP1B1 is linked to pulmonary arterial hypertension.