Tyrosine kinase inhibitors which have been tested in SCCHN include gefitinib and erlotinib, which are reversible specific EGFR TKIs, lapatinib, a reversible dual EGFR/Her2 TKI, afatinib, an irreversible dual EGFR/Her2 TKI, and PF-00299804, a potent irreversible pan-HER TKI. This evidence concerns the gene ERBB2 and head and neck squamous cell carcinoma.