The two commonly upregulated genes in the active neutrophils, macrophages, active proliferating Th, and exhausted proliferating Tcyt included the gene XAF1, a tumour suppressor that is upregulated in virus-infected cells and enhances IFN-induced apoptosis [71,72], and PYDC4, which is predicted to regulate the activation of the inflammasomes, which are intracellular bodies that coordinate the response of cells to viral infections [73] (Figure 6C). Here, XAF1 is linked to viral infectious disease.