To note, both PAH CM and PDGF-BB increased phosphorylation of Akt, ERK1/2 and p38 MAPK to a similar extent, seen in Figure 7A,C, suggesting that PAH CM could promote cell proliferation through Akt, ERK1/2 and p38 MAPK. This evidence concerns the gene MAPK3 and pulmonary arterial hypertension.