Exhausted CD8 T Cell (IMAGE) University of Pennsylvania School of Medicine Caption This is an exhausted CD8 T cell with Tox functioning in the nucleus. (White is CD8 staining at the cell surface, Pink is DNA in the nucleus, Blue is Tox in the nucleus.) Credit John Wherry, Penn Medicine 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.