A substance being studied in the diagnosis and treatment of glioma (a type of brain cancer) and other types of cancer. It binds to cancer cells in the brain and peripheral nervous system and may keep them from spreading. Chlorotoxin comes from the venom of a type of scorpion. A form of chlorotoxin made in the laboratory is called TM-601. Chlorotoxin is a type of neurotoxin. Also called CTX.