Most relevant, when FOXF1 was transfected in PAEC of three PAH patients, expression levels of selected transcripts (VEGFR2, CLDN5, TP53, and ATM) were increased (Fig. 6f)  This is consistent with restoration of angiogenesis, assessed by the Matrigel tube formation assay (Fig. 6g and Supplementary Fig. 6g), as well as PAEC migration, determined by the scratch wound assay (Fig. 6h and Supplementary Fig. 6h) and repair of DNA damage, judged by comet assay (Fig. 6i and Supplementary Fig. 6i and j). This evidence concerns the gene CLDN5 and pulmonary arterial hypertension.