Core Viewpoint - The article discusses the critical role of regulatory T cells in maintaining immune system balance, preventing autoimmune diseases, and their potential implications for medical treatments, as highlighted by the recent Nobel Prize in Physiology or Medicine awarded to three scientists for their discoveries in this field [1][9][16]. Group 1: Immune System Functionality - The immune system distinguishes between "self" and "non-self" cells, with regulatory T cells acting as mediators to suppress excessive immune responses and prevent attacks on the body's own tissues [1][9]. - T cells possess unique receptors that can theoretically identify over 10^15 different antigens, but this broad recognition capability also poses risks of mistakenly targeting self-cells [7][9]. Group 2: Research Breakthroughs - The central tolerance mechanism eliminates T cells that recognize self-proteins during their maturation in the thymus, but some self-reactive T cells can escape this process, necessitating additional regulatory mechanisms [9][15]. - The identification of regulatory T cells by the Nobel laureates has opened new avenues for research and potential therapies for autoimmune diseases and cancer treatments [9][16]. Group 3: Medical Implications - Potential therapies based on regulatory T cell mechanisms are currently in clinical trials, aiming to enhance immune responses against tumors and improve treatments for autoimmune diseases [16]. - Strategies include using interleukin-2 to promote regulatory T cell proliferation and engineering therapies to extract and expand these cells for targeted immune regulation [16].