Stuck Dividing (IMAGE) Rockefeller University Caption In some cancers, including chondroblastoma and a rare form of childhood sarcoma, a mutation in histone H3 reduces global levels of methylation (dark areas) in tumor cells but not in normal cells (arrowhead). Rockefeller scientists found that the mutation arrests the cells in a proliferative state to promote tumor development. Credit Laboratory of Chromatin Biology and Epigenetics at The Rockefeller University Usage Restrictions Image may be used only to illustrate the research described in the accompanying release. 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.