Concurrently, in BPD rats, it has been found that the levels of E-cadherin protein, which is related to cell adhesion, are significantly reduced, while the expression of ECM-related proteins, including a-SMA protein and N-cadherin, is abnormally elevated (Yang et al., 2014; Li C. et al., 2020), leading to changes in the mechanical stress of the local alveolar microenvironment and thus affecting the formation of alveoli and secondary septa. The gene discussed is SMN1; the disease is bronchopulmonary dysplasia.