EGFR is an oncogenic driver and patients with somatic mutations, particularly an exon 19 deletion or exon 21 L858R mutation, within the tyrosine kinase domain have activating mutations that lead to unchecked cell proliferation. Overexpression of EGFR causes inappropriate activation of the anti-apoptotic Ras signaling pathway, found in many different types of cancer. Icotinib is a quinazoline derivative that binds reversibly to the ATP binding site of the EGFR protein, preventing completion of the signal transduction cascade.[1]