More importantly, the ROC curve analysis of the Lasso regression model showed that the AUC values were all above 0.9, indicating the outstanding potential of the 5 hub DEGs, namely, CXCR1, CCL5, ADORA3, CCR1, and SAA1, as biomarkers for distinguishing IPAH patients, which has significant clinical feasibility in auxiliary diagnosis and disease classification. Here, SAA1 is linked to idiopathic pulmonary arterial hypertension.