EGFR and lung cancer: For example, because EGFR is known to be overexpressed in non-small cell lung cancer (NSCLC), the most common type of lung cancer [5,6], and NSCLC is treated using gefitinib—a kinase inhibitor that binds to the intracellular tyrosine kinase domain of EGFR and inhibits the signaling that drives cell proliferation and survival [6].