PTGS2 and pulmonary fibrosis: With the in depth study of the PI3K/Akt pathway, studies reported that the activation of some factors, such as mammalian target of rapamycin, vascular endothelial growth factor and reactive oxygen species and COX2 in the downstream of the PI3K/AKT signaling pathway can participate in pulmonary fibrosis (Laddha & Kulkarni, 2019; Wu et al., 2018b).