To examine whether this loss of E-cadherin is associated with increased levels of c-Jun protein, we compared a non-tumorigenic human breast epithelial cell line (HB-2) to tumorigenic breast cancer cell lines that either are metastatic (Hs578T and MDA-MB-231) or non-metastatic (MCF-7, SUM159, HCC1937 and T47D). The gene discussed is JUN; the disease is breast cancer.