 Voltage-gated Ca2+ channels (VGCCs), tetrodotoxin-resistant (TTX-R) VGSCs and rectifier-delayed potassium channels are not affected.HNTX-III and HNTX-IV are part of the Huwentoxin-I family.Toxins from the Huwentoxin-I family are thought to bind to site 1 on the sodium channels.