Associations of PM2.5, NO2, SO2, and O3 with the log-transformed LDH, total protein, CXCL10, IFN-γ, CD14, and CD62 levels in pleural effusion were determined after adjusting for age, sex, BMI, smoking, and disease category (pneumonia or CHF) (Table 3). This evidence concerns the gene CD14 and pneumonia.