Such a dataset is needed for two reasons: (1) to assess and integrate hERG safety margins for many clinical drugs that block hERG channels, are associated with TdP risk, and have high quality clinical ECG data to yield a margin threshold; and (2) to understand just how different two hERG block potency values, and by extension safety margin values, need to be for these to be interpreted as different. Here, KCNH2 is linked to torsades de pointes.