ALK and mature T-cell and NK-cell non-Hodgkin lymphoma: The most common subtypes include PTCL not otherwise specified (PTCL-NOS), extra-nodal natural killer (NK)/T cell lymphoma, nasal type (ENKTL), angioimmunoblastic T-cell lymphoma (AITL), anaplastic lymphoma kinase positive anaplastic large cell lymphoma (ALK + ALCL) and anaplastic lymphoma kinase negative anaplastic large cell lymphoma (ALK− ALCL) [6].