Furthermore, the downstream factors of TLR7 and BTK in TLR pathway, such as MYD88, IRF7, NFKB1, and JUN, and cytokines (TNF, IL1B, and IL18) were elevated in men with severe COVID-19 (Fig. 5b and Supplementary Fig. 5b). Here, NFKB1 is linked to COVID-19.