Isolation of a growth-stimulating agent from human skin fibroblast cultures.

Cell-free supernatants were harvested from cultures of human skin fibroblasts, were applied on to DEAE-cellulose columns, and the first fraction eluted with phosphate-buffered saline contained the growth-stimulating agent. The eluted fraction was then passed through a series of amicon membranes. After passing through PM-10, the filtrate stimulated growth of bovine vascular endothelial, canine myocardial, and human mammary carcinoma cells.