TET1 (1 of 2) (IMAGE) University of Copenhagen Caption In stem cells the TET1 enzyme turns specialized stem cells genes on by removing methyl groups from the genes. In specialized cells, as for example liver cells, TET1 is not present why methyl groups will turn off the stem cell genes. Credit Kristine Williams, BRIC, University of Copenhagen Usage Restrictions Grafic can be used when crediting Kristine Williams, BRIC, University of Copenhagen 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.