IL-27 is unique in that although it induces Th1 differentiation, it can antagonise the development of the Th17-cell response and limit Th-17 driven inflammation44, critical for host defence against bacterial, fungal and viral infections at mucosal surfaces40 while IL-35 induces proliferation of Treg cell populations but reduces activity of Th17 cell populations45. The gene discussed is IL27; the disease is viral infectious disease.