This document summarizes research on the pharmacological profile and binding affinity of Stichodactyla helianthus toxin (ShK) to various voltage-gated potassium channels. ShK binds with high affinity in the picomolar to low nanomolar range to several potassium channels, including Kv1.1, Kv1.3, Kv1.6 and Kv3.2. It binds with lower affinity in the micromolar range to other channels such as Kv1.2, Kv1.4, and Kv1.7. ShK has been shown to potently and selectively inhibit T lymphocyte proliferation by blocking Kv1.3 channels. Due to this immunosup