Lung cancer treatment has recently moved toward a customized approach based on the molecular characteristics of tumors: patients with EGFR mutations may show improved benefit from EGFR tyrosine kinase inhibitors (TKIs; e.g., erlotinib and gefitinib), and those with ALK translocations from ALK inhibitors (e.g., crizotinib). The gene discussed is ALK; the disease is lung cancer.