Of the cell surface activation markers tested, only CD64 (high affinity FcγRI) upregulation occurred on lung neutrophils specifically during RSV infection and not mock infection CD64 upregulation is associated with neutrophil activation in bacterial infections,36 however the functional relevance of CD64 cell surface expression on neutrophils in viral infections is not known. The gene discussed is FCGR1A; the disease is bacterial infectious disease.