What is clear is that a large majority of ALCL are associated with a specific chromosomal translocation, the t(2;5)(p23;q35), which was described in the early 1980s and was later identified to be the fusion of a kinase gene, ALK, to a nucleolar protein gene, Nucleophosmin 1 (NPM) [23]. Here, NPM1 is linked to anaplastic large cell lymphoma.