To investigate the expression data, we first hierarchically clustered (Eisen et al, 1998) the 46 pretreatment samples using a 1300-gene breast intrinsic gene set developed by Hu et al (2006), which can identify the intrinsic tumour subtypes (luminal A, luminal B, basal-like, HER2+/ER− and normal breast-like) that show significant differences in patient outcome (Sørlie et al, 2001, 2003). This evidence concerns the gene ERBB2 and neoplasm.