ERBB2 and neoplasm: Trastuzumab is a large-molecule monoclonal antibody targeted drug that can block the interaction between HER2 and its ligand, thereby promoting the activation of the signal transduction pathway;17 while Pyrotinib is an oral small molecule targeted drug that can easily penetrate the cell membrane and directly act on intracellular targets, blocking the downstream signal transduction by binding to the HER2 receptor to inhibit tumor angiogenesis, thus inhibiting tumor growth.18