Because of the aforementioned male predisposition to SCD, and the requirement in SCD of both an electrical and an ischemic substrate, here we asked whether deletion of Kcne4 in mice sex-specifically affects arrhythmia predisposition, before versus after coronary artery ligation to mimic the cardiac ischemia that, together with an electrical substrate, is thought to predispose to SCD. The gene discussed is KCNE4; the disease is Arrhythmia.