To evaluate the efficacy of metformin, NSG mice transplanted with PBMCs were orally administered metformin daily for 5 weeks.<h4>Results</h4>Mice injected with PBMCs from SS patients exhibited a significant increase in the frequency of human IL-17-producing T cells in the spleen, accompanied by enhanced infiltration of these pro-inflammatory cells into the salivary glands. Here, IL17A is linked to synovial sarcoma.