Apart from the association with pruritus, IL-31 is also thought to contribute to immune evasion in HL and in CTCL: in the tumor microenvironment, high IL-31 may shift the balance from anti-tumor Th1 responses—mediated by IFNgamma—towards immunosuppressive Th2 cytokines [68]. Here, IL31 is linked to primary cutaneous T-cell non-Hodgkin lymphoma.