ERBB2 and neoplasm: Notably, HER‐2‐E0771 cells were grafted into HER‐2 transgenic (TG) mice, where HER‐2 expression was driven by the whey acidic protein (WAP) promoter that induces expression in the cerebellum and the lactating mammary gland (Piechocki et al, 2003), so that HER‐2‐expressing orthotopic tumours would be regarded as self and host anti‐tumour immunity repressed.