ERBB2 and neoplasm: Approximately one-third of all women with primary breast cancer will develop metastatic disease (Rosen et al, 1989; Fisher et al, 2002), whereby the risk of relapse is strongly related to lymph node involvement, tumour size, grade at diagnosis (Fitzgibbons et al, 2000), lymphatic and/or vascular invasion, hormone receptor status and presence of HER2 overexpression (Pinder et al, 1994).