This study investigated the potential of oral mucosa as a route for 2019-nCoV infection by analyzing ACE2 expression. Using RNA-seq data from TCGA and FANTOMS CAGE databases and in-house single-cell transcriptomes, the researchers found that ACE2 is expressed in the oral mucosa, particularly highly enriched in tongue epithelial cells. This suggests that the oral cavity might be a high-risk site for 2019-nCoV infection.