Peripheral T-cell non-Hodgkin lymphomas (PTCL) belong to a rare (∼15% of NHL) and heterogeneous group of lymphoid malignancies, comprised of several subtypes: extra-nodal (NK/T-cell, nasal-type, enteropathy-type, hepatosplenic, subcutaneous panniculitis-like) and nodal PTCL (NOS) (not otherwise specified), anaplastic large cell lymphoma (ALCL, ALK-negative) and angioimmunoblastic T-cell lymphoma (AITL) [1, 2]. The gene discussed is ALK; the disease is mature T-cell and NK-cell non-Hodgkin lymphoma.