ERBB2 and head and neck squamous cell carcinoma: To our knowledge, this study is the first to examine heterogeneity of HER2 expression in HNSCC and to study the dual targeting of HER2/EGFR in HNSCC in the context of radiosensitization; however, our studies are supported by research into dual HER2/EGFR inhibition in pancreatic and gastrointestinal cancer29–36.