IL4 and infection: Depending on the type of infection and the pattern of PAMPs and DAMPs, APCs release certain cytokines, thereby determining CD4 T cell lineage commitment and eventually the class of antibodies [in humans, e.g., intracellular (viral and bacterial) infection: type I IFNs/IL-12, Th1, IgG1, IgG3; helminth infection: IL-4, Th2, IgG4, IgE; fungal infection: IL-23, Th17], hallmarking the close interplay between the innate and adaptive arm of the immune system (266, 368, 566).