Dr David Gallego-Ortega (IMAGE) Garvan Institute of Medical Research Caption Research led by the Garvan Institute has revealed how breast cancer cells that develop during or after pregnancy change their environment to form more aggressive tumours. Credit Garvan Institute Usage Restrictions Only for use with this story, must credit. 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.