The methylation of the SNAI2 gene negatively associated with higher tumour grade (grade 3) (OR = 0.61; 95% CI, 0.39–0.97; P = 0.038) and higher grade positively associated with the high Ki-67 proliferative index (OR = 17.34; 95% CI, 2.89–103.88; P = 0.002) (Table 4). This evidence concerns the gene SNAI2 and neoplasm.