the polypeptide growth factors , nerve growth factor , epidermal growth factor , and platelet-derived growth factor , as well as insulin do not induce ornithine decarboxylase ( l-ornithine carboxy-lyase , ec 4.1.1.17 ) unless a minimal concentration of an ornithine decarboxylase-inducing amino acid , such as asparagine , is present in the medium .
C0018284
growth factors
C0032200
platelet-derived growth factor