OGG1 and cancer: The OGG1 gene has at least twenty-five validated sequence variants that reportedly change amino acid of the protein but Ser326Cys (rs1052133) has been extensively investigated for its association with different types of cancer risk including esophageal [10], lung [11], stomach [12], thyroid [2], laryngeal [13], colorectal [14, 15], and pancreatic cancer [9].