Fehrholz et al. (58) found that as a non-specific phosphodiesterase inhibitor, caffeine could regulate the expression of CTGF and transgelin (a cytoskeletal binding and stabilizing protein) through the TGF-β/Smad pathway, and change the remodeling of airway epithelial cells, thereby achieving a protective effect against BPD on lung damage. The gene discussed is TGFB1; the disease is bronchopulmonary dysplasia.