IL6 and pulmonary arterial hypertension: Increased expression of interleukin (IL)-1β, IL-6, IL-1 receptor (R)1, and IL6R and their role in pulmonary vascular remodeling have been reported in patients with idiopathic PAH and hypoxia-induced PAH mice (Parpaleix et al., 2016; Tamura et al., 2018).