MAPK1 and pulmonary arterial hypertension: Similar to hypoxia, we found that the expression of RPS27A, MAPK1, STAT1, RPS6, FBL, RPS3, RPS2, and GART hub genes are positively correlated with apoptosis (ssGSEA score of hallmark hypoxia gene set) in the PAH (Spearman’s correlation test, p < 0.05) (Figure 7B).