The same pattern of SDCBP expression was identified in mammary epithelial cell lines: its expression was remarkably higher in ER-negative MDA-MB-231, Hs 578T and BT-549 BCa cells than that in ER-positive MCF-7 and T47D cells and in the fibrocystic disease epithelial cell MCF-10A. This evidence concerns the gene SDCBP and breast fibrocystic disease.