ERBB4 and head and neck squamous cell carcinoma: Analysis of TCGA database showed that EGFR is overexpressed in 17% (47/279) of the HNSCC patients, and the other ErbB family members, such as ErbB2 (5% - 15/279) and ErbB4 (3% - 8/279) are also overexpressed but at lower frequency.