Core Insights - The article discusses the groundbreaking discoveries by three scientists, Mary Brenner, Fred Ramsdell, and Shimon Sakaguchi, regarding regulatory T cells, which act as "safety guards" in the immune system, preventing it from mistakenly attacking the body's own cells [1][6]. Group 1: Immune System Understanding - The immune system is likened to an army that protects the body from pathogens, but pathogens can disguise themselves, complicating the immune response [1]. - Traditionally, it was believed that immune tolerance was achieved solely through a central process in the thymus, where immune cells are screened to prevent them from attacking the body [2]. Group 2: Key Discoveries - In the 1980s, Sakaguchi's research revealed that mature T cells could regulate immune responses and suppress self-reactive T cells, leading to the identification of regulatory T cells [3]. - Subsequent research by Brenner and Ramsdell provided critical evidence supporting Sakaguchi's findings, linking genetic mutations in mice to immune system dysfunction [4][5]. Group 3: Clinical Implications - The discoveries have significant clinical implications, paving the way for new therapies for autoimmune diseases and cancer, with over 200 related studies currently in clinical trials [6][7]. - Autoimmune diseases affect approximately 10% of the global population, highlighting the importance of these findings in developing treatment methods [7].