EGFR and pulmonary arterial hypertension: Accumulating evidence suggests that EGFR is closely associated with the molecular mechanism of PAH, and epidermal growth factor inhibitors such as erlotinib and dacomitinib have been used to treat PAH in animal models [40–42].Interleukin-6 (IL-6) is a pleiotropic cytokine with a wide range of biological activities such as immune regulation, hematopoiesis, inflammation, and oncogenesis.