Chlorotoxin is a chloride channel blocker which has been found in the venom of the Egyptian scorpion Leiurus quinquestriatus. The toxin has recently been reported to specifically bind to a protein complex on the surface of glioma cells containing several proteins implicated in glioma cell invasion and thus inhibit their invasive potential. Gelatinase A (matrix metalloproteinase-2 (MMP2)) is one of the components present in this complex. The anti-invasive effect of chlorotoxin seems to be mediated by binding to and direct inhibition of gelatinase A, and its surface down-regulation. Chlorotoxin is also available in bulk quantities, produced according to cGMP.