IL4 and infection: Resistance to infection is recapitulated by infecting mice with a high dose (200–400) of T. muris eggs and is mediated by a type-2 immune response that includes increased production of interleukin 4 (IL-4), IL-13, IL-25, IL-33, IL-9 and antibody isotypes IgG1 and IgE and results in worm expulsion [3, 7].