IL5 and primary cutaneous T-cell non-Hodgkin lymphoma: Increased IL-5 production by peripheral mononuclear cells from patients with Sézary syndrome together with eosinophilia was identified, suggesting that IFN-alpha and perhaps IL-12 may produce a therapeutic response in patients with CTCL and eosinophilia through the direct suppression of IL-5 production by malignant Sézary cells [116].