Deciphering hERG channels: Molecular basis of the rapid component of the delayed rectifier potassium current

► This review describes three isoforms/splice variants of the ERG protein. ► ERG1b and ERGuso modulate ERG1a channel trafficking, expression and kinetics. ► ERG1b alters kinetics resulting in more available channels and larger current. ► ERGuso leads to a reduced number of channels at the plasma membrane. ► This has implications for cardiac disease and drug development.