ZEB1 and cancer: To rule out the possibility that the acquisition of the epithelial phenotype in the fibroblasts was an effect due to BRCA1 knock-out, rather than an effect secondary to horizontal transfer of cancer mRNA, we analyzed the expression of SNAI1, SNAI2, ZEB1, ZEB2, CDH2, vimentin, fibronectin, and CDH1 in naïve fibroblasts.