Nucleophosmin-anaplastic lymphoma kinase (NPM–ALK) positive anaplastic large cell lymphoma (ALCL) is considered as a peripheral T-cell lymphoma and is associated with the t(2;5)(p23;q35) translocation, identified to be the fusion of a kinase gene, ALK, to a nucleolar protein gene, NPM1 (ref. 1). The gene discussed is ALK; the disease is peripheral T-cell lymphoma, not otherwise specified.