TMPRSS2 and COVID-19: Xu et al analyzed bulk RNA-seq profiles from public databases and suggested that ACE2 is expressed and enriched in human tongue epithelial cells.21Sakaguchi et al immunohistochemically confirmed that ACE2 and TMPRSS2 are coexpressed in the tongue epithelia of non-COVID-19 patients.8The tongue would serve as a target for SARS-CoV-2 and allow it to enter the human body.