The article reviews the regulatory mechanisms of CD4+CD25+Foxp3+ regulatory T cells (Tregs) and their role in maintaining immune homeostasis. It explores the signaling pathways of cytokines such as transforming growth factor beta (TGF-β), interleukin (IL)-2, IL-10, and IL-35, which promote Treg differentiation and enhance their immunosuppressive capabilities. Conversely, IL-6 and tumor necrosis factor alpha (TNF-α) can undermine Treg functions or even reprogram them into effector T cells. The B7 family of co-stimulatory molecules, including CTLA-4 and PD-1, plays a crucial role in regulating Treg differentiation, function, and survival. The article also discusses the potential of Treg-based immunotherapy for treating autoimmune diseases, transplant rejection, and cancer. By understanding these regulatory mechanisms, the article aims to enhance our knowledge of Treg regulation and its therapeutic potential.The article reviews the regulatory mechanisms of CD4+CD25+Foxp3+ regulatory T cells (Tregs) and their role in maintaining immune homeostasis. It explores the signaling pathways of cytokines such as transforming growth factor beta (TGF-β), interleukin (IL)-2, IL-10, and IL-35, which promote Treg differentiation and enhance their immunosuppressive capabilities. Conversely, IL-6 and tumor necrosis factor alpha (TNF-α) can undermine Treg functions or even reprogram them into effector T cells. The B7 family of co-stimulatory molecules, including CTLA-4 and PD-1, plays a crucial role in regulating Treg differentiation, function, and survival. The article also discusses the potential of Treg-based immunotherapy for treating autoimmune diseases, transplant rejection, and cancer. By understanding these regulatory mechanisms, the article aims to enhance our knowledge of Treg regulation and its therapeutic potential.