PTEN-induced putative kinase 1 (Pink1), an enzyme that promotes phagolysis of damaged mitochondria, is downregulated in IPF patients, and the degree of lung fibrosis is increased in Pink1-deficient mice, which is associated with reduced mitophagy, accumulation of malformed mitochondria, ER stress, and increased AT2 apoptotic senescence [43]. Here, PINK1 is linked to pulmonary fibrosis.