 As a medicine it is among the most potent, and in Japan only it has been used against liver cancer clinically.The biosynthesis of neocarzinostatin takes place through a convergence of the activities of a gene cluster, which includes two separate iterative type I polyketide synthase (PKS) and deoxy sugar biosynthetic pathways.The first type I PKS gene, NcsE, codes for the enediyne moiety.