Conditional overexpression of TGF-β1 in the lungs of neonatal mice and rats results in interstitial fibrosis that is comparable with BPD in humans [30,31], Tgfb3 was on the same level as in normoxic animals in the sham treated animals, but was down-regulated in lung tissue of the MNC treated animals. The gene discussed is TGFB3; the disease is bronchopulmonary dysplasia.