TLR9 and COVID-19: As would be expected from the SARS-CoV-2 viral activation pattern just described, TLR3 [20,115], TLR7 [20,115,116,117,118], TLR8 [20,56,86,115,117,118,119], TLR9 [86,115], NLRP3 [101,118,120,121], RIG-1 [122] and MDA-5 [122] are activated in patients with severe COVID-19.