SERPINE1 and lung disorder: To determine whether increased PAI‐1 is responsible for ATII cell senescence in fibrotic lung disease in vivo, a tamoxifen (Tmx) inducible, ATII cell‐specific PAI‐1 conditional knockout (Sftpc‐CreER:PAI‐1fl/fl; CKO) mouse model has been generated by gene targeting technique as deciphered in Fig. S1 (Supporting information).