KCNH2 and familial long QT syndrome: At least as important as its role in hERG-associated congenital arrhythmias is the pharmacological susceptibility of hERG to block by a variety of functionally- and structurally-diverse drugs which underlies the drug-induced form of acquired LQTS with a susceptibility to Torsades de Pointes (TdP) (Vandenberg et al., 2001; Sanguinetti and Tristani-Firouzi, 2006; He et al., 2013; Kalyaanamoorthy and Barakat, 2018).