ALK rearrangements occur in around 4–5% of NSCLC cases, the predominant one being the inversion in the short arm of chromosome 2, which creates a fusion between the echinoderm microtubule-associated protein-like 4 (EML4) gene and the ALK gene, leading to the production of the EML4-ALK fusion protein [3,140,141]. Here, ALK is linked to non-small cell lung carcinoma.