TGF-尾1 (Transforming Growth Factor-beta 1) is a multifunctional cytokine belonging to the TGF-尾 superfamily, playing a pivotal role in cell proliferation, differentiation, apoptosis, immune regulation, extracellular matrix formation, and tissue repair. Synthesized as an inactive precursor, it undergoes proteolytic activation to form a biologically active homodimer. TGF-尾1 signals through binding to TGF-尾 receptors (Type I/II), triggering both Smad-dependent (canonical) and Smad-independent (non-canonical, e.g., MAPK, PI3K) pathways. Critical in embryogenesis, wound healing, and fibrosis, TGF-尾1 exhibits dual roles in disease鈥攁cting as a tumor suppressor early in cancer but promoting metastasis in advanced stages. Dysregulation is linked to fibrotic disorders (e.g., pulmonary fibrosis), autoimmune diseases, and cancer progression. Its context-dependent functions (anti-inflammatory vs. pro-fibrotic/tumorigenic) are influenced by microenvironmental cues, making it a therapeutic target for fibrosis, cancer, and inflammatory conditions.