These pivotal roles resonate with the central role reported for these mediators in the control of cytokine networks: IFN-γ in atherogenesis [41], IL-12 (p40) in those governing T cell and macrophage responses [42], IL-13 in the pathophysiology of ulcerative colitis [43], IFN-γ, IL-12 (p40/p70) and MCP-1 in Erdheim-Chester disease [44] and eotaxin, IFN-γ, MIP-1α and MIP-1β in asthma [45]. This evidence concerns the gene IL9 and Erdheim-Chester disease.