Medulloblastoma Cells (image) Massachusetts General Hospital Caption Medulloblastoma cells secrete the developmental protein Shh, which binds to receptors in stromal cells and triggers signaling that leads to the production of PlGF. Stromal-derived PlGF then binds to Nrp1 receptors in the cancer cell and conveys signals that sustain the growth and spread of the tumor. Credit Lance Munn, Ph.D., and Nathaniel Kirkpatrick, Ph.D., Steele Laboratory for Tumor Biology, Massachusetts General Hospital. Usage Restrictions None 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.