ERBB2 and neoplasm: To analyse the activation of HER2 and its downstream related phosphoinositide-3 kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK1/2) signalling cascades or to the mammalian target of rapamycin protein (mTOR) signalling pathway, we performed Western blotting and immunohistochemical analysis of each individual animal tumour.