Immune Cells (IMAGE) Technische Universität Dresden Caption Immune cells by fluorescence microscopy: Blood stem cells remember a previous attack and produce more immune cells like these macrophages to fight a new infection Credit © Sieweke lab/CIML 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.