What is "hanatoxin"

n. Any of a group of toxins, present in the venom of funnel-web spiders, that target potassium channels

Hanatoxin is a toxin found in the venom of the Grammostola spatulata tarantula . The toxin is primarily known for inhibiting the activation of voltage-gated potassium channels, most specifically Kv4.2 and Kv2.1, by raising its activation threshold .