The immunomodulatory state is a consequence of a dominant T helper (Th) type 2 adaptive response induced or associated with these infections, and is characterized by high levels of IL-4, IL-13, IL-5, IgE and IgG subtypes IgG1 and IgG4 specific for the parasite antigens [31], recruitment of immunomodulatory populations such as regulatory T cells (Tregs: CD4+CD25+FoxP3+ cells) [30,32] and inhibitory “alternatively activated” macrophages, or M2 macrophages [33,34]. The gene discussed is IL4; the disease is infection.