TLR2 and viral infectious disease: On the one hand, with the further understanding the pathogenesis of COVID-19 and the molecular mechanisms of SARS-CoV-2 infection and its variants, which involve in TLR2 signaling induced the production of proinflammatory cytokines (hyperactive cytokine release or a cytokine storm) [110], risk stratification of mild, moderate, severe COVID-19 for the acute and long-term adverse consequences [111], and human immunity [112, 113] and genetic mechanisms of critical illness [114], we can choose better clinical strategies by valuable models [115] to combat this severe viral disease.