METTL3 and COVID-19: Loss of METTL3 in host cells reduced m6A levels in SARS-CoV-2 and host genes, and reduction of m6A in viral RNA increased RIG-I binding, which subsequently enhanced innate immune signaling pathways and inflammation-related gene expression, implying the association between m6A levels and the pathogenesis of COVID-19, which will help to achieve the intervention of COVID-19 from the perspective of innate immunity [22, 34].