The Goldilocks Effect in Aging Research (IMAGE) Salk Institute Caption Immunofluorescence analysis of pluripotent markers Nanog (red) and TRA-1-60 (green) in human induced pluripotent stem cells derived from skin fibroblasts. DNA is shown in blue. Credit Salk Institute Usage Restrictions With credit and related coverage 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.