TGFB1 and cancer: The evaluation, based on a comparison of the frequency of methylation of the TGFB1 gene promoter region with the clinical advancement according to the TNM classification, showed a more frequent methylation of the region regulating TGFB1 gene expression in the most advanced stage III and IV cancers (56% and 53%, respectively) as compared to cancers in earlier stages Io and IIo (33% and 19%, respectively).