In a model of induced loss of p53 in mammary luminal epithelial cells in mice in vivo, mammary tumors that develop after long-term suppression of p53 display claudin-low molecular characteristics with suppressed expression of claudins 3, 4 and 7 and up-regulation of the EMT genes zeb1 and twist1 and mesenchymal markers N cadherin and vimentin [38]. This evidence concerns the gene TWIST1 and breast cancer.