FOXF1 and bronchopulmonary dysplasia: Not only is the c-KIT+FOXF1+ EPC population decreased as a result of haploinsufficiency or endothelial-specific deletion of Foxf1 but this EPC population is also highly sensitive to hyperoxia exposure as seen in both human and mouse BPD lungs (Balasubramaniam and Ingram, 2009; Ren et al., 2019).