Since the expression of Kv1.3 channels is up-regulated in some cancer types, such as breast and lung cancer, melanoma, pancreatic ductal adenocarcinoma, or chronic lymphocytic leukemia (B-CLL) [4,8,9,10], inhibitors of the channels may also clinical applications in supporting the chemotherapy of these types of cancer [9,10,11]. The gene discussed is KCNA3; the disease is cancer.