Illustration of the human voltage-gated potassium (Kv) ion channel Kv1.3. Ion channels are membrane-spanning proteins that form pores in cell membranes and act as pathways for the movement of inorganic ions into and out of the cell. Kv channels are specific to potassium ions (K+) and are sensitive to voltage changes in the cell's membrane potential. Kv1.3 are found on B and T lymphocyte white blood cells and medicate the cellular immune response. Inhibitors of Kv1.3 are being investigated as immune system modulators for therapeutic use in autoimmune and neurodegenerative diseases.