Damaged DNA (IMAGE) Johns Hopkins Medicine Caption Microscopic images of a breast cancer cell with DNA damage. Left, six hours after treatment with either the epigenetic agent alone or the PARP inhibitor alone. Right, six hours after treatment with both the epigenetic drug and PARP inhibitor. Yellow staining shows trapping of the PARP enzyme at a site of DNA damage. Credit Stephen B. Baylin, M.D. and Feyruz V. Rassool, Ph.D. 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.