Immune responses to filarial infection have been shown to be stage-specific with cytokines such as IL-4, IL-2, IFN-γ, IL-5, and IL-13 in association with IgE dominating the acute phase of the infection while levels of regulatory cytokines such as IL-10 and TGF-β and the antibody isotype IgG4 being elevated during the chronic phase of the infection (79–83). This evidence concerns the gene IL2 and infection.