This study demonstrates that, unlike viral or bacterial infection alone—which predominantly upregulates mCD169 and nCD64 expression, respectively (7, 9, 10, 18, –, 23), MP infection specifically induces a synchronized phenomenon of neutrophil CD64 expression and monocyte CD169, resulting in a distinctive pattern of leukocyte activation. The gene discussed is FCGR1A; the disease is bacterial infectious disease.