IL6 and Right ventricular hypertrophy: Hypoxia leads to upregulation of miR-27b in HPAECs, inhibits the expression of PPARγ and induces the secretion of IL-6, while fibroblast growth factor 21 (FGF21) can reduce the expression of IL-6 by inhibiting miR-27b, thus alleviating PH and right ventricular hypertrophy (RVH) (35, 36).