KCNQ1 and chronic obstructive pulmonary disease: Loss- or gain-of-function of KCNQ1 results from abnormal changes in the expression of Kv7.1 and reduced or increased changes in IKs currents, ultimately leading to various cardiac arrhythmias [2], which demonstrates that the expression level of Kv7.1 in cardiomyocytes is a critical condition for its function.