TMEM37 and pulmonary arterial hypertension: The PAH concentration in LPR (694.95 ± 8.83 ng/g) and LPC (1016.62 ± 169.10 ng/g) was significantly lower than that in EPR (1875.29 ± 310.24 ng/g), EPC (1606.3 ± 130.31 ng/g), PR (1490.61 ± 165.3 ng/g), and PC (1435.63 ± 382.15 ng/g).