Cekanaviciute and colleagues found that the spore-forming bacteria from MS subjects (versus those from controls) impaired the in vitro differentiation of IL-10-secreting, regulatory T lymphocytes, consistent with a pathogenic role; however, in a small sub-study, neither the spore-forming bacteria from 2 MS or 2 control subjects had an exacerbating impact on EAE induction in antibiotic-fed mice18. The gene discussed is IL10; the disease is myeloid sarcoma.