Regarding the other miRNAs associated with the risk of death and/or sequelae, miR-1-3p is muscle-specific and its expression is diminished in heart disease (64); miR-23b-3p promotes cell differentiation and inhibits cell proliferation and angiogenesis (65); miR-141-3p targets the chemokine gene CXCL12 (66), which plays a key role in immune cell recruitment and is upregulated in severe COVID-19 (67); miR-4433b-5p is significantly down-regulated in COVID-19 patients requiring supplementary oxygen therapy (68), but its functions remain unknown. This evidence concerns the gene CXCL12 and COVID-19.