CXCL10 is highly induced in avian flu (H5N1)-infected ferrets, non-human primates, and human cells including alveolar epithelial cells and monocyte-derived macrophages [16]–[18], [32], [33], [40], and has been viewed as a prognostic marker for several viral infections [37], [39], [41], [42]. Here, CXCL10 is linked to viral infectious disease.