BMP9 receptor, ACVRL1, and its downstream target genes were inhibited in EPCs from Foxf1WT/S52F mutant mice, a model of alveolar capillary dysplasia with misalignment of pulmonary veins (ACDMPV). This evidence concerns the gene ACVRL1 and alveolar capillary dysplasia with misalignment of pulmonary veins.