In addition to chemotherapy, cetuximab combined with the CDK4/6 inhibitor palbociclib,423 VEGF monoclonal antibody bevacizumab,424 or immunotherapy (pembrolizumab425 and nivolumab426) also showed promising clinical activity and safety profiles in R/M-HNSCC patients, including platinum-resistant and cetuximab-resistant patients. Here, CDK4 is linked to head and neck squamous cell carcinoma.