TLR1 and COVID-19: Furthermore, induction of TLR1/2-MyD88 signaling by SARS-CoV-2 infection activates IRF1 to induce IL27p28 mRNA expression (Fig. 9D) and produce functional IL27, which induces a robust IL27-STAT1-dependent pro-inflammatory and antiviral response associated with induction of the antiviral state in COVID-19 patients (Fig. 9E), which is associated with disease severity.