Telomeres in Mouse Embryonic Fibroblasts (image) Centro Nacional de Investigaciones Oncológicas (CNIO) Share Print E-Mail Caption Telomeres (red) in mouse embryonic fibroblasts; DNA damage (green) caused by ERK inhibition. ERK is an enzyme in the RAS pathway whose inhibition leads to TRF1 deactivation. The arrow shows telomere damage. Credit CNIO Usage Restrictions None 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.