EML4 and non-small cell lung carcinoma: Within 3 years of the initial discovery of EGFRMUT addiction in NSCLC, a small proportion of NSCLCs (around 4 % to 6 %) was reported to harbour a small inversion within chromosome 2p, resulting in the fusion of the echinoderm microtubule-associated protein-like 4 (EML4) gene and the anaplastic lymphoma kinase (ALK) gene.