To determine whether GM play a role in the development of BD, researchers transplanted mixed fecal samples from patients with active BD into mice with experimental autoimmune uveitis (EAU) and observed increased intraocular inflammation; a large amount of inflammatory cell infiltration throughout the retina, choroid, and vitreous cavity; and increased production of inflammatory cytokines including IL-17 and interferon gamma (IFN-γ) (Ye et al., 2018). Here, IL17A is linked to Behcet disease.