Human tumour tissue (IMAGE) Uppsala University Caption Microscopic image of human tumour tissue (coloured magenta) and various immune cells: T cells (green and red), B cells (yellow) and NK (natural killer) cells (white). Activated T and B cells are depicted in cornflower blue, while the nuclei of all the cells are shown in the darker blue shade. Credit Iliana Kyriaki Kerzeli Usage Restrictions Only to be used when reporting about research by Iliana Kyriaki Kerzeli 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.