Recombinant Human KIT Ligand/Stem Cell Factor-alpha is a single, non-glycosylatedpolypeptide chain containing 165 amino acids.KIT Ligand (KITLG) is the recently identified ligand for the kit tyrosine kinase receptor, ismapped to the mouse S1 locus. This pleiotropic cytokine, alternately known as Stem CellFactor (SCF), Mast Cell Growth Factor (MGF) and Steel-Factor (SF), plays essentialroles in gametogenesis, melanogenesis and early stages of hematopoiesis. In vitro andin vivo, SCF can stimulate the proliferation of mature, as well as the proliferation andmaturation of immature, mast cells. On purified primitive human and mousehematopoietic precursors, SCF acts in a synergistic manner with various growth factors, such as IL1, IL3, IL6, IL7, and EPO, to induce myeloid, erythroid and lymphoid lineagecolony formation. The finding that SCF is also expressed in the nervous systemsuggests a possible role for SCF in the development of the nervous system.