For example, several studies have routinely tested the effects of Kv11.1 inhibitors on different cancer cells but, despite their success in impeding cancer cell proliferation, use of these Kv11.1 blockers as anticancer therapeutics is discouraged due to the associated, often lethal severe cardiac arrhythmias [73, 77, 78, 92, 93]. This evidence concerns the gene KCNH2 and cardiac arrhythmia.