AKT1 and bronchopulmonary dysplasia: Also, the expression level of hsa-miR-103a-3p related to the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) signalling pathway was decreased in cord blood-derived exosomes from the BPD group compared with the NBPD group, which is significantly involved in cell proliferation, cell migration, and tube formation.