ERBB2 and breast carcinoma: Studies on HER receptors in breast carcinoma so far focused mainly on HER1 and HER2, only some groups have evaluated the expression of the entire HER family (Bieche et al, 2003; Hudelist et al, 2003; Lodge et al, 2003; Witton et al, 2003; Abd El-Rehim et al, 2004; Wiseman et al, 2005; Bianchi et al, 2006).