ShK toxin, isolated from the Caribbean sea anemone (Stichodactyla helianthus), is an inhibitor of the voltage-dependent potassium channel (Kv1.3 channel). It competes with dendrotoxin I and α-dendrotoxin in binding to rat brain synaptosomal membranes and promotes acetylcholine release. Additionally, ShK toxin reduces K+ currents in cultured rat dorsal root ganglion neurons and inhibits T lymphocyte proliferation [1] [2].