Fibroblasts play a critical role in chronic inflammation and wound healing. In this study, a fibroblast growth-stimulating factor was purified from the exudate of car-rageenan-induced inflammation in rats. The purified protein was a disulfide-linked homodimer. Amino acid sequence analysis of the peptides generated by cleavage with cyanogen bromide and proteinase V8 resulted in identification of the protein as S100A9. Recombinant S100A9 as well as its disulfide-linked homodimer stimu-lated the proliferation of fibroblasts at a similar con-centration of the purified protein. .
