ZEB1 and melanoma: Direct down regulation of ZEB1 or ZEB2 using siRNAs confirmed these results and lead us to suggest that ZEB2 may not participate in the down regulation of E-cadherin in human breast cancer cell lines, in agreement with the finding of Caramel et al. in melanoma [12], but contrasting with earlier reports suggesting direct down regulation of E-cadherin by ZEB2 alone [4].