Renal Cyst Fluid Contains Growth Factors (IMAGE) University of California - Santa Barbara Caption Renal cyst fluid contains growth factors that cause the excessive proliferation and cyst growth associated with polycystic kidney disease. Credit UCSB 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.