EGFR and non-small cell lung carcinoma: In NSCLC, EGFR deregulation is prevalent, characterized by protein overexpression in 85 % of cases, gene mutations in 10–40 %, and gene amplification in approximately 10 % Protein overexpression (assessed by immunohistochemistry) or gene copy number (assessed by fluorescence in situ hybridization) lack consistent prognostic or predictive value.