IL27 and normal pressure hydrocephalus: After removing SNP (rs10774624) associated with confounders, results indicated that IL-17A (OR, 0.35; 95%CI, 0.18–0.68; P = 1.97E-03) still significantly reduced the risk of obstructive hydrocephalus, and IL-27 (OR, 0.75; 95%CI, 0.58–0.97; P = 2.96E-02) also remained a significantly protective factor against normal-pressure hydrocephalus (shown in Table 1).