Bovine Platelet-Derived Growth Factor-BB (PDGF-BB) is a homodimeric growth factor composed of two PDGF-B chains that plays a key role in cell proliferation, migration, angiogenesis, and tissue repair in cattle (Bos taurus). PDGF-BB signals primarily through platelet-derived growth factor receptor-β (PDGFR-β) and PDGFR-α/β receptor complexes, activating intracellular pathways including PI3K/AKT, MAPK, and STAT, which regulate fibroblast proliferation, smooth muscle cell growth, and extracellular matrix production. In cattle, PDGF-BB is produced by platelets, macrophages, endothelial cells, and fibroblasts and is released during tissue injury, inflammation, and wound healing. It plays important roles in connective tissue repair, vascular remodeling, and dermal regeneration, particularly following injury or infection. PDGF-BB signaling is also relevant in bovine health conditions such as mastitis and inflammatory tissue damage, where it contributes to tissue repair and remodeling of mammary gland structures. Additionally, PDGF-BB participates in fibrotic responses and stromal cell activation during chronic inflammation. As a regulator of cell growth, angiogenesis, and tissue regeneration, bovine PDGF-BB is important for studies of wound healing, mammary gland biology, fibrosis, and regenerative processes relevant to cattle health and livestock productivity.