HEY1 and breast cancer: As shown in Figure 6C and 6D, enhanced expression of p53 reversed the expression pattern of either epithelial markers, such as E-cadherin, or mesenchymal markers, such as vimentin and fibronectin, in NUMB-knockdown breast cancer cells; however, it had no significant effect on the expression of NICD and HEY1 in NUMB-knockdown breast cancer cells.