Although exact mechanism that induced expansion of regulatory T cells in i27-exosome treated mice is not clear, it is of note that i27-Breg immunotherapy ameliorates encephalomyelitis and uveitis in mice by propagating inhibitory signals that convert conventional B cells to regulatory lymphocytes secreting IL-10 and/or IL-35 in the eye, brain, or spinal cord (15). The gene discussed is IL10; the disease is uveitis.