Thank you for your comment. The NCI Thesaurus (NCIt) drug hierarchy focuses on the primary clinical mechanism of action rather than chemical relationships. The term Antibiotic is classified under Anti-Infective Agent in NCIt. As a group these agents act on a variety of bacterial components to inhibit infection through mechanisms that can disrupt cell membranes or inhibit bacterial cell wall synthesis, bacterial protein synthesis, folate synthesis, or bacterial DNA gyrase activity. Antineoplastic antibiotics are indeed related to antibiotics but given the NCIt hierarchy, parenting Antineoplastic Antibiotic under Antibiotic would imply that these agents are used as anti-infective agents. Antineoplastic antibiotics are designed to fight against cancer through various mechanisms of action which inhibit the proliferation of neoplastic cells, including the targeting of DNA to block DNA replication, transcription and protein synthesis. As a group, these agents are not designed to optimize their antibacterial activity, even though they may have some. Therefore, parenting Antineoplastic Antibiotic under Antibiotic, and thus under Anti-Infective Agent, misrepresents this class of agents. Consequently, we have this concept under the parent of Antineoplastic Agent only.