These cadmium-transformed breast epithelial (CTBE) cells displayed characteristics of basal-like breast carcinoma, including ER-α negativity and HER2 (human epidermal growth factor receptor 2) negativity, reduced expression of BRCA1 (breast cancer susceptibility gene 1), and increased CK5 (cytokeratin 5) and p63 expression. This evidence concerns the gene KRT5 and breast carcinoma.