SCGF-alpha and -beta are hematopoietic growth factors that exert their activity at early stages of hematopoiesis. The SCGFs are non-glycosylated species-specific cytokines that can support growth of primitive hematopoietic cells, and, in combination with EPO or GM-CSF, promote proliferation of erythroid or myeloid progenitors, respectively. Recombinant Human SCGF-beta is a 25.0 kDa polypeptide containing 227 amino acid residues.