Zebra Finch (Taeniopygia guttata) Stem Cell Factor (SCF) (also known as KIT ligand, KITLG, mast cell growth factor, or steel factor) is a cytokine and growth factor involved in hematopoiesis, stem cell maintenance, and cellular development in this avian species. SCF belongs to a group of hematopoietic growth factors that regulate the survival, proliferation, and differentiation of stem and progenitor cells. It functions by binding to the c-Kit receptor (CD117), a receptor tyrosine kinase expressed on hematopoietic stem cells, melanocyte precursors, mast cells, and germ cells, activating intracellular signaling pathways including PI3K/AKT, MAPK, and JAK/STAT that promote cell survival and proliferation. In zebra finches, SCF is produced by stromal cells, fibroblasts, endothelial cells, and epithelial cells, and exists in both membrane-bound and soluble forms, enabling both localized and systemic regulation of c-Kit–expressing cells. SCF contributes to blood cell development, pigmentation, and reproductive cell development during growth and maturation. Because zebra finches are widely used as model organisms for neurobiology, vocal learning, and developmental biology, characterization of SCF in this species supports broader studies of stem cell regulation, developmental signaling pathways, and conserved growth factor functions across vertebrates.