Nearly 30 different ALK fusion protein partners have been described, with echinoderm microtubule-associated protein-like 4 (EML4) and nucleophosmin (NPM) being the most prevalent in NSCLC and anaplastic large cell lymphoma (ALCL) occurring in 3% to 5% and more than 50%, respectively [58]. Here, NPM1 is linked to anaplastic large cell lymphoma.