Fig. 2 H4K20ac in Human Cells (IMAGE) Osaka University Caption We confirmed the existence of H4K20ac in human cells by measuring accurate mass of the peptide with K20ac. Credit Osaka University 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.