Blocks voltage-gated sodium channels (Nav). Causes tail erection, scratching and a reduction in mobility at a dose level of 1.40 mg/mouse. 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. 60 (Tx2-9) subfamily.