However, as shown in Table 5, the APE1 polymorphism was associated with p53 mutation in nonsmokers (OR, 3.45; 95% CI, 1.39–8.53; P = 0.007) and in squamous cell carcinoma samples (3.21; 1.38–7.47, P = 0.007). This evidence concerns the gene APEX1 and squamous cell carcinoma.