Filtered (IMAGE) Johns Hopkins Medicine Caption Sinuses of mice that inhaled filtered air. The sinus surface is an intact barrier as seen by the presence of proteins that hold the cells together such as E-cadherin (red). Credit Ramanathan lab 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.