SNAI1 and pulmonary fibrosis: PI3K p85 was also proven as miR-503 target, and the activation of PI3Kp85/Akt/mTOR/Snail pathway facilitated the development of EMT and pulmonary fibrosis (Yan W. et al., 2017), overexpression of miR-503 has been shown to inhibit silica-induced pulmonary fibrosis by inactivating that pathway (Yan W. et al., 2017).