In addition, patients in the lung infection group had significantly higher levels of serum pro-calcitonin (PCT), C-reactive protein (CRP), amyloid A (SAA), blood neutrophil-to-lymphocyte ratio (NLCR), erythrocyte sedimentation rate (ESR), as well as Birmingham vasculitis activity score (BVAS) than patients in the other two groups (p < 0.05). The gene discussed is CRP; the disease is vasculitis.