A platelet-derived endothelial cell growth factor cDNA has been cloned, sequenced and expressed using the Saccharomyces cerevisiae PRB1 promoter. Soluble recombinant platelet-derived endothelial cell growth factor constituted 0.5-1.0% of total soluble protein. Yeast soluble protein extracts containing recombinant platelet-derived endothelial cell growth factor stimulate the growth of calf pulmonary artery endothelial cells in vitro.