CDH1 and breast cancer: Stimulated by the above results obtained from transfected NMuMG cells, we switched to a well-studied human breast cancer cell line MDA-MB-231 since, (i) these cells are highly invasive and metastatic and are characterized by a mesenchymal phenotype (20); (ii) they do not express E-cadherin and (iii) they exhibit extensive CDH1 promoter hypermethylation (8).