Spleen-derived growth factor, SDGF-3, is identified as keratinocyte growth factor (KGF).

A heparin-binding mitogen rat for rat hepatocytes was partially purified from bovine spleen by a combination of heparin-affinity, cation-exchange and gel-filtration chromatography. Besides stimulating rat hepatocytes, this factor, which was designated spleen-derived growth factor-3 (SDGF-3), exhibited mitogenic activity for mouse epidermal keratinocytes but not mouse fibroblasts. Its apparent epithelial specificity and heparin-binding properties corresponded to those of keratinocyte growth factor (KGF). These findings, together with the fact that the mitogenic activity of SDGF-3 was abolished by a neutralizing monoclonal antibody specific for KGF, identify this bovine spleen-derived hepatocyte mitogen as KGF.