EGFR and non-small cell lung carcinoma: The small-molecule inhibitors for egfr (gefitinib and erlotinib) show modest antitumour activity when administered as single agents in unselected patient populations with non-small-cell lung carcinoma, but they show a positive clinical response in a subset of patients that harbour somatic mutations in the egfr gene and whose tumours may be dependent on expression of those mutated genes 13.