Single cell sequencing in lungs (IMAGE) Texas Biomedical Research Institute Caption Using single-cell RNA sequencing, the researchers identified the different cell types present in the lungs before COVID-19 infection (left), in the first few days of infection (center), and towards the end of infection (right). Each color represents a different cell type. The red represents macrophages, which clearly increase at three days post infection. Credit Texas Biomed Usage Restrictions Can reuse with credit License Original 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.