ERBB2 and neoplasm: Thirdly, tumour pathological and morphological characteristics may play a role, as suggested by Elebro and colleagues, who reported a significant variation in HER2 and HER3 expression according to AMP subtype (intestinal type (HER2 6%, HER3 51%) vs pancreato-biliary (HER2 0%, HER3 17%) type) [38].