Regulatory T cells (Tregs), characterized by CD4+CD25+FOXP3+ expression (1), are pivotal mediators of immune homeostasis that also drive tumor immune evasion through multiple mechanisms, including direct suppression of effector T cells, secretion of inhibitory cytokines (e.g., IL-10, TGF-β), and modulation of antigen-presenting cells (2, 3). The gene discussed is TGFB1; the disease is neoplasm.