EGFR stands for epidermal growth factor receptor. This type of receptor is a protein in the epidermal growth factor family (EGF family) and is encoded by the EGFR gene. Epidermal growth factor ignites cell growth and variation by binding to the EGFR. A growth factor receptor is the first location on cells in which the signaling occurs for cell differentiation and proliferation. EGFR in cancers may be amplified, over-expressed, or mutated.

EGFR mutation testing is an important step in the treatment-decision pathway for patients with NSCLC. Tyrosine kinase inhibitors (TKIs) and monoclonal antibodies (mAbs) that specifically target mutated EGFR have been created to treat patients with EGFR-mutant NSCLC. Identifying patients with alterations in the EGFR gene can help determine what anticancer agents to use in the treatment of their disease