Regulatory T-cells, often abbreviated as Tregs, are a specialized subset of T-cells that play a crucial role in maintaining the body's immune balance. They help prevent excessive immune responses that can lead to autoimmune diseases, where the body mistakenly attacks its own tissues. Tregs achieve this by suppressing the activity of other immune cells, ensuring that the immune system responds appropriately to threats without overreacting. These cells are characterized by the expression of specific markers, such as CD4 and CD25, and they produce anti-inflammatory cytokines like IL-10 and TGF-β. Tregs are essential for promoting tolerance to self-antigens and maintaining a healthy immune environment, making them vital for overall immune system function.