KCNJ2 and mitral valve disorder: They identified many mitral valve prolapse risk loci based on the chromatin accessibility variation which provided an indicator for mitral valve prolapse research.339 Ventricular arrhythmia is one of the symptoms of long QT syndrome type 7, which is mainly caused by the mutation of KCNJ2 gene.340 Recently, Chen et al. repaired the mutant in hiPSCs derived from human patients.