To further confirm the implication of STAT3/KLF5 axis in PAH, healthy-PASMC were treated for 48 h with increasing doses of pro-PAH factors [26-28] like ET1 (10 nM), PDGF (30 ng.mL-1) and IL-6 (20 ng.mL-1). This evidence concerns the gene KLF5 and pulmonary arterial hypertension.