Li X, Lu C, Fan D, Lu X, Xia Y, Zhao H, Xu H, Zhu Y, Li J, Liu H, et al. Human Umbilical Mesenchymal Stem Cells Display Therapeutic Potential in Rheumatoid Arthritis by Regulating Interactions Between Immunity and Gut Microbiota the Aryl Hydrocarbon Receptor. Front Cell Dev Biol. 2020;8:131.