CXCR6 regulates parts of lung memory CD8+ T cells during an unrelenting immune response to aero‐pathogens, including other coronaviruses.[202]CXCR6 is a tissue‐residence gene that is found in higher quantities in expanded CD8+ T cells compared to non‐expanded cells in moderate SARS‐CoV‐2 infections.[203] High amounts of total CD8+ T cells are found in moderate SARS‐CoV‐2 infection compared to severe infection. This evidence concerns the gene CXCR6 and infection.