IL4 and primary cutaneous T-cell non-Hodgkin lymphoma: Also Ohmatsu et al. [25] demonstrated augmented circulating IL-31 in CTCL; but also they demonstrated the presence of several cytokines (i.e. IL-4 and IL-6) and chemokines (i.e. CXCL12, CXCL13, CCL17 and CCL26) fundamental in CTCL which might be modulated by IL-31.