MTOR and malignant tumor of neck: Targeted therapy focuses on oncogenic signaling pathways involved in carcinogenesis of head and neck cancer, such as epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER-2), vascular endothelial growth factor receptor (VEGFR), insulin growth factor-1 receptor (IGF-1R), MET receptor, transcriptional factor nuclear factor-kappa B (NF-κB), and phosphatidylinositol-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway [10, 11].