Echinoderm microtubule-associated protein-like 4 (EML4)–anaplastic lymphoma kinase (ALK) is an oncogenic fusion protein that results from an inversion on the short arm of chromosome 2, leading to the expression of a constitutively active tyrosine kinase which drives tumour progression in 5% of cases of NSCLC [7]. The gene discussed is EML4; the disease is neoplasm.