A family of 4 disulfide-linked homodimeric cytokines. The family members are PDGF-AA, PDGF-BB, PDGF-CC, and PDGF-DD. There is also one heterodimeric protein, PDGF-AB. All PDGF is synthesized in an inactive precursor form that is processed to active. Isoforms are synthesized by various parts of the body at various times. In adults, large amounts of PDGF is stored in platelet granules to be released upon platelet activation. The other cell types that produce PDGF include monocyte derived lineages, megakaryocyte lineages, endothelial cells, fibroblasts, and a variety of cell lines (transformed cells)

PDGF is a potent chemoattractant for neutrophils and mesenchymal cells. It is also a potent activator of mesenchymal cells. Activity occurs through two distinct PDGF receptors (alpha and beta). Both receptors belong to the receptor tyrosine kinase family of proteins and elicit their effects through signal transduction to the nucleus inducing transcription.