S100A4 and pulmonary arterial hypertension: The decrease in BMPR2 levels in S100A4‐stimulated and PAH cells was RAGE dependent, as BMPR2 levels were restored when cells were previously transfected with siRAGE measured at both the mRNA and protein levels (≥50% increase, n=3 to 5 cell lines, P<0.05; Figure 3).