Therefore, we conclude on the cell-intrinsic and microenvironmental effects of OX-40 which are maintained in this model, but further studies in the immunocompetent murine systems will be necessary to completely understand the role played by OX-40 in tumor-immune crosstalk in CTCL. The gene discussed is TNFRSF4; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.