FMS-related Tyrosine Kinase 3 Ligand (FLT-3 Ligand) is a growth factor important for the prolife ion of hematopoietic cells. FLT-3 Ligand binds to, and transmits signals through, the receptor tyrosine kinase known as FMS-like Tyrosine Kinase-3 (FLT-3). FLT-3 Ligand promotes long-term expansion and differentiation of pro-B cells in the presence of IL-7 or in combination of IL-7 and IL-3. FLT-3 Ligand can stimulate the prolife ion of cells expressing murine FLT-3 receptors. Recombinant FLT-3 Ligand is a non-glycosylated Protein, containing 155 amino acids, with a molecular weight of 17.6 kDa.