ERBB2 and breast cancer: To estimate the clinical relevance of these gene products associated with gain 7/8 tumours, their mRNA expression as well as that of established molecular markers (i.e. HER2, EGFR, p53 and bcl2) was quantified by real-time RT–PCR on samples from 160 patients with stage I/IIA breast cancer with known clinical records and long-term follow-up (Supplementary data).