By WGCNA analysis, we screened the up-regulated hub genes of TMF1, GOLGB1, ARMC8, PRPF40 A, EIF3 A, ROCK2, EIF5B, CCP110, and KRR1 associated with PAH, and in order to verify the potential role of eIF3a in the development of pulmonary arterial hypertension, MCT-induced PAH rat model was constructed successfully. The gene discussed is KRR1; the disease is pulmonary arterial hypertension.