The diagnostic value of hub genes in recognizing PAH tissues from normal control presented excellent diagnostic value with AUC of 0.889 (95% confidence interval (CI): 81.73%-96.07%), sensitivity of 75.9%, and specificity of 96.0% in CCL5; AUC of 0.854 (95% CI: 75.81%-95.08%), sensitivity of 93.1%, and specificity of 68.0% in VCAM1; and AUC of 0.853 (95% CI: 76.01%-94.61%), sensitivity of 74.1%, and specificity of 96.0% in SPP1 (Figure 6). This evidence concerns the gene CCL5 and pulmonary arterial hypertension.