Dr. Michele Ardolino, The Ottawa Hospital (IMAGE) The Ottawa Hospital Caption Dr. Michele Ardolino (pictured here) and Dr. David Raulet and their colleagues discovered that Natural Killer cells may play an important role in the body's response to cancer immunotherapy drugs called checkpoint inhibitors. Credit The Ottawa Hospital Usage Restrictions Only for use in stories about this research. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.