CXCR1 and bacterial infectious disease: CXCR1 is a powerful neutrophils chemotactic factor that recruit neutrophils to lower respiratory tract in LRTIs.[26] IL1R1 is receptor of the proinflammatory cytokines IL‐1 and involved in many cytokine‐induced immune and inflammatory responses after bacterial infection.[27] These results indicated that gene modules clustered from mNGS data also reflect the host response after respiratory infection.