SHPK and Autoimmunity: In autoreactive pathogenic T cells Kv1.3 has been shown to be the main voltage-gated potassium channel and blocking the channel with the ShK peptide inhibits the autoreactive pathogenic T cells in animal models of autoimmunity in vivo (Beeton et al., 2001) and in cell cultures of human T cells in vitro (Wulff et al., 2003).