ERBB2 and breast cancer: To determine the expression pattern of ZEB1 in different subtypes of human breast cancer, we performed immunostaining of ZEB1 in the tissue arrays consisting of 98 luminal (ER and/or PR positive, HER2 negative or positive), 22 HER2+ (ER and PR negative, HER2 positive) and 47 triple-negative breast cancer (TNBC; ER and PR negative, HER2 negative) tumour samples, as well as the matched normal samples.