Single-factor analysis showed that the following were significantly greater in the DRG than NRG: total fever duration, the hospitalization time, C-reactive protein (CRP) level, lactate dehydrogenase (LDH) level, D-dimer level, pulmonary lesions involving two or more lobes, a large amount of pleural effusion, the time to interventional bronchoscopy, and mucus plugs formation. The gene discussed is CRP; the disease is Pleural effusion.