Indeed, nasopharyngeal epithelial cells of COVID-19 patients exhibited significantly higher expression of TLR2 and TLR4 as compared to controls (340), and TLR4 and its downstream elements (including Myd88, IRAK1 and TRAF6, and NF-κB - dependent genes) were significantly upregulated in PBMCs from 20 human COVID-19 patients (341). This evidence concerns the gene TLR4 and COVID-19.