NPM1 and anaplastic large cell lymphoma: The first evidence of ALK oncogenic properties emerged in 1994, when the fusion protein nucleophosmin (NPM)-ALK originated by the chromosomal translocation t(2;5)(p23;q35) was identified and associated with an aggressive form of non-Hodgkin T-cell lymphoma, known as anaplastic large-cell lymphoma (ALCL) 3.