NOS3 and infection: Beyond CXCL5, our machine-learning approach highlighted several other novel candidates: PDGF-B, Galectin-1, CXCL11, ANGPT1, EGF, TIE2, MCP-2, and NOS3 that each outperformed CXCL5 in discriminating a dormant infection from uninfected joint replacements (Fig. 4).