ChEBI: Bortezomib is l-Phenylalaninamide substituted at the amide nitrogen by a 1-(dihydroxyboranyl)-3-methylbutyl group and at N(alpha) by a pyrazin-2-ylcarbonyl group. It is a dipeptidyl boronic acid that reversibly inhibits the 26S proteasome. It has a role as an antineoplastic agent, a proteasome inhibitor, a protease inhibitor and an antiprotozoal drug. It is an amino acid amide, a member of pyrazines and a L-phenylalanine derivative. It derives from a boronic acid.NCI Thesaurus (NCIt): Bortezomib is a dipeptide boronic acid analogue with antineoplastic activity. Bortezomib reversibly inhibits the 26S proteasome, a large protease complex that degrades ubiquinated proteins. By blocking the targeted proteolysis normally performed by the proteasome, bortezomib disrupts various cell signaling pathways, leading to cell cycle arrest, apoptosis, and inhibition of angiogenesis. Specifically, the agent inhibits nuclear factor (NF)-kappaB, a protein that is constitutively activated in some cancers, thereby interfering with NF-kappaB-mediated cell survival, tumor growth, and angiogenesis. In vivo, bortezomib delays tumor growth and enhances the cytotoxic effects of radiation and chemotherapy.