While T cells physiologically do not express receptors for IL-13 [52], the latter have been detected in high concentrations in malignant T cells from cutaneous localizations of CTCL as well as from the bloodstream of SS patients [53] supporting a role of IL-13 receptors as biomarkers of malignancy throughout each stage of CTCL. The gene discussed is IL13; the disease is primary cutaneous T-cell non-Hodgkin lymphoma.