For example, we have shown in a previous experimental and computational study that the hERG activator NS1643, one of the most effective and best characterized hERG activators (Hansen et al., 2006), successfully restores APD toward healthy durations and reduces arrhythmia triggers, but is associated with an increase in the VW, i.e., the substrate for arrhythmias, due to effects on the post-repolarisation refractory period (Peitersen et al., 2008). The gene discussed is KCNH2; the disease is cardiac arrhythmia.