Aurora A and TPX2 (IMAGE) Howard Hughes Medical Institute Caption Once the Aurora A protein (blue) and TPX2 protein (red) learned how to fit together, they stayed that way forever. Dark dots represent amino acids that remain unchanged throughout evolution. Light dots represent amino acids that differ between the ancient and modern proteins. Credit Dorothee Kern/Brandeis University/HHMI Usage Restrictions Use with credit. 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.