Furthermore, variants at loci 3p21.31 and 9q34.2 (encompassing SLC6A20, LZTFL1, FYCO1, CXCR6, XCR1, CCR9, and ABO) have been associated with Spanish and Italian patients with COVID-1911, and different variants affect predisposition toward life-threatening illness in COVID-19 patients of different ancestries9. This evidence concerns the gene CCR9 and COVID-19.