We further analyzed the expression of genes in apoptosis‐related granzyme/perforin, TNF, XAF1, and FAS pathway [14], and found that, in CD8+ T cells, most granzyme/perforin, TNF, XAF1 and FAS pathway members (e.g., GZMB/H, XAF1, TNFRSF10B, IRF1, FAS, CASP3/8) exhibited an upregulated trend in brucellosis patients (Figure 5G), especially for those from the acute stage. Here, XAF1 is linked to brucellosis.