ALK and non-small cell lung carcinoma: In 2007, an echinoderm microtubule-associated protein-like 4 (EML4)-anaplastic lymphoma kinase (ALK) fusion gene was discovered in NSCLC5, and it has since been shown that approximately 3–5% of NSCLC patients harbor ALK-rearrangement and display dramatic responses to ALK-tyrosine kinase inhibitors (ALK-TKIs)6,7.