Zebrafish (Danio rerio) Transforming Growth Factor Alpha (TGF-α) is a member of the epidermal growth factor (EGF) family of growth factors, which includes epidermal growth factor (EGF), amphiregulin, betacellulin, epiregulin, and heparin-binding EGF-like growth factor (HB-EGF). In zebrafish, TGF-α is synthesized as a membrane-bound precursor (pro–TGF-α) that undergoes proteolytic cleavage to release a soluble ligand capable of binding the epidermal growth factor receptor (EGFR). Activation of EGFR stimulates intracellular signaling pathways such as MAPK/ERK, PI3K/AKT, and JAK/STAT, which regulate cell proliferation, epithelial growth, differentiation, and tissue regeneration. In zebrafish, TGF-α is expressed in tissues including the skin, gastrointestinal tract, developing nervous system, and regenerating organs, where it contributes to embryonic development, epithelial maintenance, and regenerative processes. Zebrafish are particularly known for their ability to regenerate tissues such as the heart, fins, and skin, and EGFR signaling involving TGF-α participates in cell proliferation and tissue remodeling during regeneration. Because zebrafish are widely used as a genetic and developmental model organism, characterization of zebrafish TGF-α supports studies of EGFR signaling, vertebrate development, epithelial biology, and regenerative mechanisms relevant to both fundamental biology and human disease research.