(IMAGE) Proceedings of the National Academy of Sciences Caption Electron micrograph of Hervey pteropid retrovirus following release from a human cell. Higher quality images are available at: https://drive.google.com/open?id=13aaYUKeMl6BW2HwDb_YeRTiszLtJxI9F Credit Image credit: Megan Dearnley. 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.