Compact Mucin (IMAGE) University of North Carolina Health Care Caption This is an electron microscopy of large, compact mucin protein that keeps mucus too thick and sticky, causing problems for CF patients. Credit M. Kesimer/J. Griffith, UNC School of Medicine Usage Restrictions credit properly 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.