In the comparison among the non-CAD group, mild CAD group, and severe CAD group, the expression levels of IL-4 (P = 0.005 and P = 0.017), IL-12p70 (P < 0.001 and P < 0.001), and IL-17 (P < 0.001 and P < 0.001) were significantly lower in severe CAD group than both in non-CAD group and mild CAD group, IFN-α level are lower in severe CAD group than in non-CAD group (P = 0.014) but no statistical difference between severe CAD group and mild CAD group (P = 0.109), and all the cytokine levels did not differ significantly between non-CAD group and mild CAD group. The gene discussed is IL17A; the disease is coronary artery disorder.