Results are shown as number (N) and proportion of the examinees with certain phenotype. P value was obtained using χ2 -test. P < 0.05 was considered statistically significant. PON1 - paraoxonase 1. CIN - cervical intraepithelial neoplasia. AA phenotype - low activity homozygotes. AB phenotype - middle range activity heterozygotes. BB phenotype - high activity homozygotes. This evidence concerns the gene PON1 and cervical squamous intraepithelial neoplasia.