OGG1 and cancer: Genotyping of CYP1A1, GSTP1, GSTM1, GSTT1, and OGG1 was performed, and CYP1A1 enzyme activity and urinary oxidative damage biomarkers were assessed.<h4>Results</h4>The most robust differences were observed in gastric tissue, where 13 individual POPs and selected chemical classes remained significantly different between cancer and control groups after FDR correction.