Nucleus of a cell in BPTA syndrome (IMAGE) Charité - Universitätsmedizin Berlin Caption Nucleus (dotted line) of a human cell. The HMGB1 protein (green) that is mutated in BPTA syndrome forms a hard layer at the nucleolus (pink), causing the developmental disorder. Credit © MPIMG | Henri Niskanen Usage Restrictions Image may be used to cover the accompanying press release, provided full credit is given. License Original 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.