CXCL9 and COVID-19: Acute COVID-19 features an imbalanced host response marked by elevations of IL-1β, IL-6, IL-8, TNF-α and interferon-inducible chemokines (e.g., CXCL9/CXCL10) that govern myeloid recruitment, T-cell positioning, angiogenesis, and tissue remodeling.