Description: Factor that induces terminal differentiation of late-developing B-cells to immunoglobulin secreting cells. (www.uniprot.org) Produced in E. coli. Dimeric, non-glycosylated polypeptide chain containing two 113 amino acids chains. The ED50 as determined by the dose-dependant stimulation of the proliferation of TF-1 cells was found to be < 0.15ng/ml.