BAK1 and vitiligo: To date, only one study by Wang et al. reported that exosomes derived from human umbilical cord MSCs improved vitiligo by reducing CD8+ T cells infiltration and promoting regulatory T cell expansions in skin, thereby exerting immunosuppressive effects, as well as by ameliorating oxidative stress-induced melanocyte injury through the delivery of miR-132-3p and miR-125b-5p targeting Sirt1 and Bak1, respectively [22].