CCM Mouse Heart (image) University of Pennsylvania School of Medicine Share Print E-Mail Caption Immunofluorescence microscopy image of a CCM mutant mouse heart is shown. The image is stained for Klf4 (green), myocardium (red) and nuclei (blue). Loss of endocardial CCM signaling leads to an up-regulated Klf4 level. Credit Lili Guo 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.