NTRK1 and neoplasm: Apatinib, a novel receptor tyrosine kinase inhibitor that highly selectively inhibits the binding of VEGF and vascular epidermal growth factor-2 (VEGFR-2), blocking the activation of mitogen-activated protein kinase (MAPK) signaling pathway, achieving the purpose of anti-tumor neovascularization and preventing further proliferation and metastasis of tumor cells [13].