Combination of human umbilical cord mesenchymal stem (stromal) cell transplantation with IFN-γ treatment synergistically improves the clinical outcomes of patients with rheumatoid arthritis Xiao He1,2,3, Yi Yang1,4, Mengwei Yao1,5, Lei Yang6, Luoquan Ao1,2, Xueting Hu1,2, Zhan Li1,2, Xiaofeng Wu1,2, Yan Tan1,2, Wei Xing1,2, Wei Guo1,2, Joseph A Bellanti7, http://orcid.org/0000-0002-5611-4774Song Guo Zheng8, http://orcid.org/0000-0002-1026-2210Xiang Xu1,2,5 1 Department of Stem Cell &...