LAP3 and viral pneumonia: To create such signatures for bacterial versus viral pneumonia, we curated publicly available transcriptomic datasets for respiratory infections from whole-blood and peripheral mononuclear blood cells (PBMCs), filtered these datasets for human peptidases (using the enzyme nomenclature term ec:3.4.-.-), and applied a computational multicohort framework designed to integrate gene expression data (multicohort analysis using aggregated gene expression [MANATEE]) (27) across 33 unique study cohorts (Fig. 2A and SI Appendix, Tables S1 and S2).