Interleukin 10 (IL-10) is the founding member of the IL-10 family of class II cytokines. All of the IL-10 cytokine family members have a four-helix bundle consisting of α-helical folds. Upon binding to its receptor, IL-10 activates signaling through JAK1 and STAT3. It is produced by dendritic cells, macrophages, and CD4+ T regulatory cells, as well as mast cells, NK cells, neutrophils, and regulatory B cells, under specific stimulating conditions (Saraiva & O'Garra). IL-10 can inhibit the activation of certain immune cells while it promotes the function of B cells, and facilitate healing process. Specifically, this cytokine is important for the function of T regulatory cells as it is a potent suppressor of effector T cell proliferation and cytokine production. Also, IL-10 produced by a subset of macrophages inhibits activation and production of pro-inflammatory cytokines by neighboring macrophages, thus allowing a level of self-regulation. IL-10 enhances B cell proliferation, immunoglobulin secretion, and class II MHC expression (Ouyang et al.).