SERPINE1 and pulmonary fibrosis: In the process of human skin and pulmonary fibrosis, the uPAR of fibroblasts was knocked out to produce more ECM, but when the uPA inhibitor plasminogen activator inhibitor-1 (PAI-1) was knocked out, collagen secretion was inhibited and fibroblast proliferation and migration were significantly suppressed [61,62,63].