TLR4 and COVID-19: TLR2 and TLR4 sense viral proteins, and the expression levels of molecules related to the TLR2- and TLR4-inflammatory signaling molecules are upregulated in in COVID-19 patients, which suggest the involvement of TLR2 and TLR4 signaling in the induction of pathological inflammation during COVID-19 (Sohn et al., 2020).