The deletion of heterozygous copy number variants and point mutations in FOXF1 is the primary cause of alveolar capillary dysplasia with misalignment of pulmonary veins (55, 56), which is a rare and fatal disease characterized by severe progressive hypoxia and pulmonary hypertension (57). Here, FOXF1 is linked to alveolar capillary dysplasia with misalignment of pulmonary veins.