In vitro and in vivo studies have demonstrated a synergistic effect of Palbociclib with Cetuximab in HNSCC—this is postulated to arise from the ability of Cetuximab to inhibit the induction of CCND1 and EGFR activation that is usually triggered by CDK 4/6 inhibitors [53]. This evidence concerns the gene EGFR and head and neck squamous cell carcinoma.