To confirm that EZH2 functions as a gatekeeper of epithelial identity in breast carcinoma cells we analysed whether inhibition of EZH2 led to the transcriptional activation of mesenchymal genes in cell lines derived from different types of metastatic breast adenocarcinomas: MCF-7 cells (ER+/PR±/Her2−), SKBR3 cells (ER−, PR−, Her2+) and MDA-MB-231 cells (ER−/PR−/Her2−). The gene discussed is ERBB2; the disease is breast adenocarcinoma.