However, while IKr inhibition does play a prominent role in drug-induced TdP, which is the basis for the acceptance of hERG inhibition as an indicator of potential cardiac toxicity, it is important to recognize that the effects of drugs on other ion channels, such as increasing the plateau generated by sodium or calcium current, or decreasing other potassium currents, may also contribute to drug-induced QT prolongation. The gene discussed is KCNH2; the disease is torsades de pointes.