To investigate CRB3 expression in human mammary epithelial cells, we examined CRB3 mRNA and protein levels in a non-tumorigenic cell line (MCF 10A) and five breast cancer cell lines (MCF7, T-47D, BT-474, MDA-MB-231(MM231) and MDA-MB-453(MM453)). This evidence concerns the gene CRB3 and breast carcinoma.