In the following, the results recently obtained by our group through the extensive application of microarray technologies will be summarised and commented on, with the scope of defining the pathobiological characteristics of PTCL/NOS, tracing the borders between it and AITL on the one hand and anaplastic large cell lymphoma kinase (ALK)-negative ALCL on the other, and drawing attention to potentially novel prognosticators and therapeutic targets.19–22, 27. Here, ALK is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.