However, as observed with the expression of Fas, malignant T cells in advanced CTCL frequently lack expression of functional receptors and/or downstream signaling mediators for IL-10 and TGF-β, essentially rendering them resistant to the suppressive activities of these cytokines [82, 86, 110, 111]. The gene discussed is TGFB1; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.