TLR7 and systemic lupus erythematosus: Although the human TLR7Y264H variant is sufficient to induce lupus in mice with no clear additive effects of Rnaseh2b hemizygosity apart from increased type I IFN gene transcripts, an exacerbating role of this variant in humans may occur in the presence of environmental stimuli, including ssRNA viruses such as SARS-CoV-2 that are dependent on TLR7 immunity43.