STAT3 and atrial fibrillation: Furthermore, the AF from OC patients is able to readily induce the expansion of CD14+HLA-DR–/low MDSC depending on IL-6/IL-10-STAT3 signaling pathway; these AF-induced CD14+HLA-DR–/low MDSC suppress the T-cell proliferation and effector function by STAT3-controlled ARG1 and iNOS expression.