Mouse Heart with Human Blood Vessels (IMAGE) University of Illinois Chicago Caption This is a mouse heart section showing human progenitor cells that formed functional human blood vessels. Purple color signifies human blood vessels, red staining signifies the blood vessels of the mouse that received the human cell implants. Credit Jalees Rehman. Usage Restrictions None 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.