Weakly nhibits voltage-gated sodium channels Nav1.7/SCN9A. High concentration of the toxin (3 uM) inhibits Nav1.7/SCN9A currents by 79%. 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.