Finally, it is worthy to note that although not included in the present study due to the resource limitation, it would be great to further elucidate detailed antivirus mechanism and perform in vivo efficacy study with the human ACE2 gene engineered animal models, which would help to complete the evidence chains for the clinical translation of the Emetine as an anti-COVID-19 therapy. This evidence concerns the gene ACE2 and COVID-19.