Severe COVID-19 was frequently complicated by an uncontrolled inflammatory response—the so-called “cytokine storm”—including the excessive release of endotheliitis-associated chemokines, such as interleukin-6 (IL6), interferon alpha and gamma (IFNα and IFNγ), C-X-C Motif Chemokine Ligand 10 (CXCL10), and Tumor Necrosis Factor alpha (TNFα). This evidence concerns the gene IFNG and COVID-19.