In our studies, the OGG1 (codon 326) heterozygous genotype decreased bladder cancer risk, especially in smokers with OR = 0.55 (0.34–0.89) (p = 0.014) [21] and prevented high grade tumors as compared to neoplasms of low malignant potential (Figure 2). This evidence concerns the gene OGG1 and urinary bladder carcinoma.