MT3 and breast cancer: The analysis of cultured non-cancerous (hTERT-HME1) and breast cancer cell lines (MCF-7, SK-BR-3, BT-474, MDA-MB-231 and MDA-MB-231/BO2) revealed the presence of high levels of MT3 in the cytoplasmic fractions of hTERT-HME1 and MDA-MB-231 cells, and lower amounts in the cytoplasmic fractions of SK-BR-3 and BT-474 cells.