National Institutes of Health Clinical Center - Special Clinical Studies Unit (SCSU), a specialized biocontainment patient-care unit. The negative-pressure anterooms on the left (take note of the white room pressure monitor at the upper right side of the door frame) lead to negative-pressure patient rooms. The negative airflow is used to reduce the risk of transmission by respiratory aerosolization to other parts of the hospital. National Institutes of Health is an agency of the United States Department of Health and Human Services.