FOSL1 and pulmonary arterial hypertension: In rat models of PAH induced by pulmonary artery banding or MCT, Wnt/β-catenin activation enhances the mRNA and protein expression of periostin, CTGF, and COL3 by activating FOSL1 and FOSL2.277 This process drives the differentiation of fibroblasts into myofibroblasts, ultimately leading to PAH and RV failure.277