KCNH2 and torsades de pointes: Since hERG assays alone can lead to false positives in predicting TdP risk and repolarization abnormalities, Kramer et al. measured concentration-response relationships of hERG, Nav1.5 peak (the fast sodium current, INa), and Cav1.2 (the L-type calcium current, ICaL) currents for 32 torsadogenic and 23 non-torsadogenic drugs from multiple pharmacological classes (Kramer et al., 2013).