DKK1 and injury: Several of these lung development molecules are also dysregulated in our model.(Fig 4) PPARγ, which was also an upregulated molecule in our study, is important for normal lung maturation.[30] Furthermore, beneficial effects have been achieved with stimulation of PPARγ, e.g. by rosiglitazone in the rat model of hyperoxia-induced lung injury.[31–33] A second upregulated molecule is DKK1, which is an inhibitor of WNT-signaling.