One aspect of cardiac safety pharmacology evaluates the pro-arrhtmic risk of drugs in vitro. However, the effect of drugs may be altered by variations in cell membrane cholesterol levels. Knowledge about the impact of cholesterol levels on the response of cardiac ion channels to drugs will be obtained by utilizing in vitro cell systems that express cardiac ion channels. The response of several ion channel interfering drugs will be evaluated and compared between “healthy” control cells and cholesterol remodelled conditions.