IFNγ has also been implicated in the pathogenesis of sarcoidosis, an autoimmune disease characterized by a Th1 dominant cytokine profile, with high levels of IL-12, IL-18, IFNγ, and IP-10, in the bronchoaleveolar lavage [141,142,143,144,145], it remains to be established whether treatment with recombinant IFNγ would induce or exacerbate underlying sarcoidosis as has been reported in patients treated with IFNα [121,122,123,124,125,126,127] and in patients treated with IFNα combined with IFNγ [146]. This evidence concerns the gene IL18 and sarcoidosis.