Sudden death as a side effect of action of non-antiarrhythmic drugs is a major 
pharmacological safety concern facing the pharmaceutical industry and the health 
regulatory authorities. A number of drugs have been withdrawn from the market in 
recent years due to cardiovascular toxicity associated with undesirable blockade 
of hERG potassium channel. Pharmaceuticals of widely varying structure have been 
shown to interact with hERG. Defining the molecular features that confer hERG 
inhibitory activity has therefore become a focus of considerable computational 
and statistical modeling efforts. Some of the approaches are aimed primarily at 
filtering out potential hERG blockers in the context of virtual libraries, while 
others involve understanding structure-activity relationships governing 
hERG-drug interactions. The ability of models to produce structural hypotheses 
that can be tested by the project teams has become the key prerequisite driving 
their organization-wide adoption.