We measured serum levels of IL-5, IL-10, IL-12, and interferon-gamma (IFN-γ) at diagnosis in AITL and other common subtypes of nodal T-cell lymphoma including peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), ALK-negative anaplastic large cell lymphoma (ALCL) or ALK-positive ALCL between September 2008 and December 2014. Here, IFNG is linked to mature T-cell and NK-cell non-Hodgkin lymphoma.