SD rats fed in normoxia and saline injection were taken as control group in Figure 1A, Single thin layer of ECs expressing vWF at EC to EC junctions immediately adjacent to smooth muscle cells, However, αSMA and vWF were increased in PAH model compared with control group, and PAH model vessel ECs layer dissociated, some of lumen cells was co-express of vWF and αSMA, accompanied part of endothelial cells migrate into inner layer of the vessel. Here, VWF is linked to pulmonary arterial hypertension.