A naturally occurring serine derivative diazo compound with antineoplastic properties, Azaserine functions as a purine antagonist and glutamine analogue (glutamine amidotransferase inhibitor) that competitively inhibits pathways in which glutamine is metabolized. An antibiotic and antitumor agent, Azaserine is used in clinical studies as a potential antineoplastic agent. Check for "https://www.cancer.gov/about-cancer/treatment/clinical-trials/intervention/C289" active clinical trials using this agent. ("http://ncit.nci.nih.gov/ncitbrowser/ConceptReport.jsp?dictionary=NCI%20Thesaurus&code=C289" NCI Thesaurus)