NSCLC patients who carry an EGFR activating mutation and a fusion protein between the N-terminal portion of the echinoderm microtubule-associated protein-like 4 protein and the intracellular signaling portion of the anaplastic lymphoma kinase tyrosine kinase receptor (EML4-ALK) are sensitive to tyrosine kinase inhibitors (TKIs). The gene discussed is EML4; the disease is non-small cell lung carcinoma.