EML4 and non-small cell lung carcinoma: Anaplastic lymphoma kinase (ALK) rearrangements account for approximately 3%–5% of non-small cell lung cancer (NSCLC), and the echinoderm microtubule-associated protein-like 4 gene (EML4) and ALK fusion (EML4-ALK) is the most common ALK rearrangement in NSCLC patients.