IGF1 and bronchopulmonary dysplasia: With the rapid development of molecular genetic research, a number of genes closely related to BPD have been discovered, such as VEGF-α, TGF-β, IGF-1, fibronectin 1, p21, FoxA1, etc. To a certain extent, the changes of the expression levels of these genes in BPD lung tissues can reflect the development trend of BPD (Ameis et al., 2017).