Single-cell immune analysis in bronchoalveolar lavage (BAL) suggested that mild COVID-19 has mainly anti-inflammatory macrophages; in contrast, in critical illness, hyperinflammatory macrophages promote the release of cytokines and chemokines like IL-6, IL-8, IL-1β, TNF, CXCL10, CCL8, CCL20, CXCL2, CXCL3, CCL3, CXCL3, and CCL4 [38,39] (Figure 1B). The gene discussed is CXCL3; the disease is COVID-19.