NPPB and idiopathic pulmonary arterial hypertension: In the small cohort of male patients, we found elevated NTproBNP levels in IPAH patients (n = 9) vs. controls (n = 19; 284.3 ± 96.2 ng/L vs. 63.1 ± 26.3 ng/L; p < 0.01) while the elevation of IL-6 and sRAGE plasma concentrations in male IPAH patients versus male controls did not reach statistical significance (Figure S1A–F).