The administration of 1 × 109 CFU/30 μL/mouse of MRSA was sufficient to induce pneumonia in mice, as indicated by the significant increase in levels of pro-inflammatory cytokines and chemokines, such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemoattractant protein-1 (MCP-1), chemokine ligand-1 (CXCl-1), and interleukin-1β (IL-1β), along with lung colony-forming unit (CFU) and the wet-to-dry weight (W/D) ratio. The gene discussed is CCL2; the disease is pneumonia.