This toxin binds to the surface of glioma cells, and inhibits their proliferation without having effects on normal brain cells. In this context, this toxin has been described as a chloride channel inhibitor (probably ClC-3/CLCN3) by causing its internalization via caveolae (PubMed:16520829). It has also been described to selectively interact with MMP2 (in complex with MT1-MMP (MMP14) and TIMP2), to inhibit its enzymatic activity and to decrease its presence at the cell surface (PubMed:12454020). Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Is under phase I clinical trial as BLZ-100 by Blaze Bioscience Inc. as a fluorescent imaging agent that labels tumor tissue to enable more complete and precise surgical resection. BLZ-100 is composed of the chlorotoxin peptide covalently bound to the near-infrared fluorophore indocyanine green. Does not interact with MMP-1, MMP-3 and MMP-9. Was tested in clinical trial under the name TM-601 for treatment of malignant glioma. Belongs to the short scorpion toxin superfamily. Chloride channel inhibitor family. Chlorotoxin entry