Tubular-like vessels in dish (IMAGE) Penn State Caption Two proteins can trigger the signaling cascades needed to help differentiate stem cells into endothelial cells that can form tubular-like vessels in a dish, according to a team led by Penn State researchers. The finding has implications for developing drug-testing platforms and other clinical applications. Credit Lian Lab/Penn Stte Usage Restrictions May only be reproduced with credit License Original 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.