Taraseviciene-Stewart et al. reported severe PAH in rats treated with chronic hypoxia and vascular endothelial growth factor (VEGF) receptor blocker SU-5416; the PAH model rats showed significant PAEC apoptosis in the early stages followed by precapillary arterial occlusion because of endothelial cell hyper proliferation; monocrotaline-induced PAH model also confirmed that endothelial cell apoptosis played a significant role in the pathogenesis of PAH 18,19. This evidence concerns the gene VEGFA and pulmonary arterial hypertension.