In PAFs, hypoxia upregulates HIF-1α and subsequently downregulates miR-29a-3p expression by increasing Smad3, thereby increasing α-SMA and COL1 expression to promote ECM remodeling.131 Additionally, studies indicate that TGF-β stimulation of PAFs activates the Wnt/β-catenin pathway, facilitating pulmonary fibrosis by downregulating E-cadherin while upregulating N-cadherin and α-SMA.12,369 TGF-β stimulation of human PAFs inhibits the phosphorylation of GSK3β at Ser9/21, thereby activating the Wnt/β-catenin pathway. The gene discussed is ACTA1; the disease is pulmonary fibrosis.