MET and osteosarcoma: Inhibitory molecules of receptor and non-receptor tyrosine kinases targeting epidermal growth factor receptor, nerve growth factor receptor, ErbB-2/neu, insulin-like growth factor-1 receptor, hepatocyte growth factor receptor (met/HGF-R), platelet-derived growth factor receptors, and Janus family protein kinases have been investigated as potential chemotherapeutic agents for the treatment of osteosarcoma, for their roles in reducing tumor cell growth, motility, invasiveness, and colony formation [14, 15].