EGFR and head and neck squamous cell carcinoma: For example, targeting EGFR ligand binding with cetuximab in HNSCC showed high toxicity when combined with copanlisib (NCT02822482)39 but was well-tolerated when combined with alpelisib (NCT02282371 40, NCT01602315 41) and showed antitumor activity (NCT02282371)40.