Many cases of head and neck squamous cell carcinoma (HNSCC) are caused by human papillomavirus (HPV); however, HNSCCs can be caused by a variety of factors, including p16 INK4A inactivation (an inhibitor of cyclin-dependent kinase 4A) and overexpression of the oncogene cyclin D1. This results in the stimulation of cyclin-dependent kinase 4 and 6 (CDK4/6). Overexpression of cyclin D1 can also cause resistance to epidermal growth factor receptor (EGFR) inhibitors. To overcome this resistance, rese...