Transforming growth factor-beta (TGF-β) is a multifunctional cytokine that plays a crucial role in regulating cell growth, differentiation, and immune responses. It is involved in various biological processes, including tissue repair, inflammation, and the development of certain diseases. TGF-β exists in three isoforms: TGF-β1, TGF-β2, and TGF-β3, each with distinct functions in the body. TGF-β signals through specific receptors on cell surfaces, activating intracellular pathways that influence gene expression. Dysregulation of TGF-β signaling is associated with several conditions, such as cancer, fibrosis, and autoimmune diseases, highlighting its importance in maintaining cellular homeostasis and overall health.