Loss of TAp63 in MECs and mammary cancer cells also leads to: (1) loss of cell polarity through the regulation of Scrib and TAZ after serial transplantation, (2) an accumulation of early TICs in serially transplanted mammary glands, and (3) an accumulation of cells with increased tumor-initiating capabilities in tumors derived from the MCF7-shTAp63 orthotopic mammary tumor mouse model. This evidence concerns the gene SCRIB and breast cancer.