IL17A and allergic asthma: The ability of IL-23 to induce IL-17 production in macrophages is consistent with the recent observations showing that IL-17 production by macrophages contributes to allergic asthma and that IL-23 protection against plasmodium berghei infection in mice is partially dependent on IL-17 from macrophages (Song et al., 2008; Ishida et al., 2013).