In a separate study of Sjogren’s syndrome, a long-term autoimmune disease, S100A4 signaling via olfactory ecto-mesenchymal stem cell-derived (OE-MSC) exosomes promoted IL-6 production in MDSCs via TLR4 signaling, which led to activation of the JAK2/STAT3 pathway (29) (Figure 2). The gene discussed is S100A4; the disease is autoimmune disease.