ALK and anaplastic large cell lymphoma: Anaplastic lymphoma kinase-positive (ALK+) ALCL is characterized by a specific chromosomal translocation, t(2;5)(p23;35) which fuses the ALK gene on chromosome 2 with the nucleophosmin (NPM) gene on chromosome 5, resulting in a NPM-ALK fusion protein, ALK overexpression and constitutive tyrosine kinase activity [2].