However, only 3−7% of non-small cell lung cancers (NSCLC) carry ALK rearrangement, which is mostly driven by an in-frame fusion of echinoderm microtubule associated protein like 4 (EML4) and ALK, both located on 2p23 and approximately 12 Mb apart. This evidence concerns the gene EML4 and non-small cell lung carcinoma.