ALK and non-small cell lung carcinoma: Recently, by screening a retroviral complementary DNA expression library generated from a NSCLC patient tumor sample, a rearrangements in the anaplastic lymphoma kinase gene (ALK) and echinoderm microtubule-associated protein-like 4 (EML4) have been identified as a result of a small inversion within the short arm of chromosome 2 between the N -terminal half of EML4 and the intracellular kinase domain of ALK [18].