In addition to AMPK, PGC-1α is another master regulator of metabolic reprogramming and an inducer of mitochondrial biogenesis, and we previously discovered that thyroid hormone (T3) inhibits lung fibrosis by restoring mitochondrial health and function through a PGC-1α–dependent pathway (11, 13). This evidence concerns the gene PPARGC1A and pulmonary fibrosis.