HLA-G and graft versus host disease: MSC-EV treatment was also tested in a therapy-refractory GvHD patient, who showed GvHD clinical symptoms improvement and remained stable for several months (Kordelas et al., 2014): MSC-EV preparations contained high concentrations of IL-10, TGF-β, and HLA-G that paralleled with the decrease in the number of both PBMCs releasing IL-1β, TNF-α, and IFN-γ and stimulated NK cells releasing TNFα- or IFN-γ (Kordelas et al., 2014).