KCNE1 is a member of the potassium channel KCNE family. KCNE1 protein plays a crucial role in regulating voltage-gated potassium channels, particularly in forming I_Kr channel, which is essential for cardiac repolarization. KCNE1 protein interacts with HERG channel, a key component of cardiac action potential, and proper function is vital for maintaining normal heart rhythm. Mutations in KCNE1 gene can lead to severe cardiac conditions, including congenital long QT syndrome, highlighting KCNE1′s importance in both cardiac health and disease. KCNE1 gene is located on chromosome 21, and expression is tightly regulated in various tissues, ensuring potassium ion flow is appropriately modulated during cellular excitability.