TGFB1 and bronchopulmonary dysplasia: Identifying injury biomarkers for the lungs of preterm infants and future risk of BPD is a research priority (7), Of the many potential candidates, TGF-β1 inhibits KGF expression (23), and reduces surfactant production in vitro by AT2 cells (24) and the higher TGF-β1 levels of the control pigs coincided with lower surfactant production.