In the nodal T cell lymphomas, the major subtypes are PTCL, not otherwise specified (PTCL-NOS), angioimmunoblastic T cell lymphoma (AITL), anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) and ALK-negative ALCL. The gene discussed is ALK; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.