NFKB1 and pulmonary arterial hypertension: Early on in the disease process, increased apoptosis within the endothelial layer leads to survival of cells with an apoptosis‐resistant phenotype, resulting in proliferation, which is a hallmark of later disease.3 We and others have shown that pulmonary vascular endothelial cells in patients with idiopathic PAH (IPAH) demonstrate markers of increased inflammation, such as nuclear factor kappa B (NF‐kB) activation.4 Moreover, in an in vitro condition, endothelial cells produce cytokines that are also found circulating in the plasma of patients with IPAH and correlate with worse survival.5