Piero Cipollone, a member of the European Central Bank's executive board, said the ECB's interest rate decision should not ignore the tightening effect on monetary policy of unwinding past asset purchases. The Italian official told an event organised by MNI that while policy rates remained the main tool for adjusting the ECB's stance, the role of quantitative tightening in influencing financial and funding conditions - through yield curves or bank lending - should also be taken into account.