The most common subtypes include peripheral T-cell lymphoma, non-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). This evidence concerns the gene ALK and angioimmunoblastic T-cell lymphoma.