The CDH1 and CTNNB1 genes, which encode the proteins E-cadherin and β-catenin respectively, are two crucial factors involved in the regulation of the EMT process [5], therefore, we proposed the hypothesis that single nucleotide polymorphism (SNP) in CDH1 and CTNNB1 genes would contribute to BC development and progression. The gene discussed is CTNNB1; the disease is breast cancer.