Strict regulation of the balance between IL-10 production and the pro-inflammatory immune response during infection is essential to achieve clearance of the pathogen in the absence of immunopathology, while at the same time avoiding the establishment of chronic infection 3 IL-10 production by TLR4-activated macrophages or dendritic cells (DCs) requires both MyD88 and TRIF signals 4. The gene discussed is TLR4; the disease is infection.