Ion channel impairing toxin that inhibits voltage-gated sodium channels. The recombinantly expressed toxin shows a weak activity against Nav1.7/SCN9A, and shifts the voltage dependence of channel activation to more depolarized potentials. Expressed by the venom gland. The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin. Belongs to the neurotoxin 10 (Hwtx-1) family. 18 (Hntx-VII) subfamily.