Microscope (IMAGE) Technical University of Denmark Caption The scientists first screened beneficial RNAi targets. Afterwards, they looked at combinations of silencing, leading to a so-called semi-rational approach. The research has now been published in PNAS Credit DTU Usage Restrictions None 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.