Atlantic Salmon EGF (Epidermal Growth Factor) is a growth factor peptide belonging to the EGF family of ligands, which also includes transforming growth factor-α (TGF-α), amphiregulin (AREG), heparin-binding EGF-like growth factor (HB-EGF), betacellulin (BTC), and epiregulin (EREG) that signal through the epidermal growth factor receptor (EGFR) to regulate cell proliferation, differentiation, and tissue repair. In Atlantic salmon (Salmo salar), EGF is expressed in epithelial tissues, skin, gill epithelium, and gastrointestinal tract, where it plays important roles in epithelial maintenance, mucosal integrity, and tissue regeneration. Binding of EGF to EGFR activates conserved intracellular signaling pathways such as MAPK/ERK and PI3K–AKT, promoting cell proliferation, survival, and regeneration of epithelial tissues following injury or environmental stress. In salmon biology, EGF signaling is particularly relevant to skin and gill health, which are critical barrier tissues exposed to aquatic pathogens and environmental changes. Because Atlantic salmon are economically important in aquaculture, EGF and related growth factor pathways are studied in fish physiology and aquaculture research to better understand epithelial repair, mucosal immunity, and tissue regeneration, helping improve disease resistance, wound healing, and overall fish health in aquaculture systems.