Analysis of intracellular Ca2+ dynamics, AP measurements, stimulation by noradrenaline, and treatment with the antiarrhythmic drug flecainide in the patient-specific hiPSC-CMs recapitulated the clinical phenotypes of LQTS and CPVT, showing, for the first time, that mutations in the TECRL gene are associated with inherited arrhythmias with clinical features of both LQTS and CPVT [133]. The gene discussed is TECRL; the disease is familial long QT syndrome.