ERBB2 and neoplasm: In contrast, most type II tumours carry gain of function mutations in the TP53 gene and, at lower extent, mutation on (F-box/WD repeat-containing protein 7) FBXW7, (AT-rich interactive domain-containing protein) ARID1A or (Receptor tyrosine-protein kinase erbB-2) ERBB2 gene amplification [4,19].