Illustration of Clock Kinase CK1 (image) University of California - Santa Cruz Share Print E-Mail Caption Casein kinase 1 (CK1) regulates a core clock protein called PERIOD. A new study explains how mutations in either CK1 or PERIOD can throw off the timing of biological clocks in animals from fruit flies to humans. Credit Illustration by Clarisse Ricci/UCSD Usage Restrictions For use only with news coverage of this research. Share Print E-Mail 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.