EGFR and adenocarcinoma: Although erlotinib or crizotinib are approved by the Food and Drug Administration (FDA) with companion diagnostics for advanced NSCLC patients with adenocarcinoma with certain EGFR mutations or ALK gene rearrangements, drug sensitive EGFR mutations are found in only 10% of Caucasian patients and ALK gene rearrangements in 2%–7% in the United States [2,3].