TNFAIP6 and bronchopulmonary dysplasia: Human recombinant TSG-6 was injected intraperitoneally into PBD mouse models at PN2 and 4 to investigate whether TSG-6 in WJMSC-Exos acts as one of the mediators in improving the BPD models, which results in significant immunomodulation and an overall lung architecture improvement.