Sub-grouping of MS patients into relapsing-remitting (RRMS) and secondary progressive (SPMS) disease revealed that T lymphocytes of SPMS patients had significantly higher Kv1.3 current amplitudes (Figure 1B, p < 0.001) and channel membrane density (Figure 3A2, p < 0.001) than T lymphocytes of RRMS patients. The gene discussed is KCNA3; the disease is secondary progressive multiple sclerosis.