Temporal RNA expression of Cxcr3 in SARS-CoV-1-infected mouse lung appears delayed with a sharp rise at 7 dpi, contrasting to 2 dpi peaks for its ligands (Fig. 3C, upper panel) and coincides with infiltration of macrophages and lymphocytes late in lung infection at a time when viral titers drop in the mice [46, 47] The appearance of CXCR3 at the infection site may be a biomarker for recovery. Here, CXCR3 is linked to infection.