Although it is possible that some of the cells in BAL fluid of patients with moderate disease are comprised of tissue-resident NK cells and memory T cells which express high levels of CXCR3 and CXCR6 at the transcriptional and protein levels (12, 13), our data strongly suggest specific infiltration of NK cells and T cells from peripheral blood into the lung in COVID-19 patients with moderate disease. This evidence concerns the gene CXCR6 and COVID-19.