In particular, BALFs from severe or mild COVID-19 patients show the upregulation of IL-6, IL-1β, and several chemokines, such as CXCL8, CXCL1, and CXCL2, critical for neutrophils recruitment into the inflamed lung; CXCL17, CCL2, and CCL7, required for monocyte recruitment; and CXCL9, CXCL10, and CXCL11, which mediate T cell migration [53]. This evidence concerns the gene CXCL9 and COVID-19.