Tooth enamel (IMAGE) University of Alaska Fairbanks Caption Scientists used samples of human tooth enamel, similar in size to these samples of wolf tooth enamel, to examine two immune proteins: immunoglobulin G and C-reactive protein. Credit Photo courtesy of Tammy Buonasera Usage Restrictions Credit must be given to the creator. Only noncommercial uses of the work are permitted. No derivatives or adaptations of the work are permitted. License CC BY-NC-ND 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.