Fifty-three percent of the Roquinsan/+ mice that developed AITL-like disease were characterized by multiple features of AITL tumors such as lymphadenopathy, perturbed nodal architecture, prominent vascularization, splenomegaly, hypergammaglobulinemia, and increased numbers of oligoclonal or clonal proliferating Tfh cells (PD1high CXCR5+ Bcl-6+) accompanied by GC B cells. Here, CXCR5 is linked to angioimmunoblastic T-cell lymphoma.