IL-17–induced reduction of OPC proliferation and MBP expression in cultures were prevented by Kv1.3 antagonist, but antagonist alone did not alter proliferation and MBP expression (Figure 2), suggesting that Kv1.3 is involved in MS-related myelin damage, and Kv1.3 blockade affects OPC cell cycle particularly under pathological conditions. The gene discussed is IL17A; the disease is myeloid sarcoma.