IFNγ levels (n = 53; 9 patients did not have remnant pericardial fluid for evaluation) were significantly higher in definite TB than non–TB pericardial effusions (median, 93.7 pg/mL [IQR, 26.1–325.1] vs 0.0 [0.0–0.0]; P < .0001; Figure 2A). The gene discussed is IFNG; the disease is pericardial effusion.