CRP (HR = 1.34, 95% bCI 1.04; 1.74), IL-13 (HR = 1.29, 95% bCI 1.06; 1.54), IL-17B (HR = 1.25, 95% bCI 1.02; 1.53), and IL-17C (HR = 1.23, 95% bCI 1.01, 1.49) were all associated with severe PPH. The gene discussed is IL13; the disease is pulmonary arterial hypertension.