Recurrent Neu-induced (i.e. HER2+) mammary tumours also display an EMT phenotype.82 There is, therefore, a crucial need to identify novel therapeutic opportunities in CL breast cancer, not only because it is a poorly understood molecular subtype, but also because its gene expression patterns are highly representative of a large proportion of resistant and recurrent tumours in human breast cancer patients. The gene discussed is ERBB2; the disease is breast cancer.