Returning to the context of the interaction between miRNAs and ACE2/TMPRSS2 in the development of acute respiratory distress syndrome associated with COVID-19, we must remember the previously reported downregulation of ACE2 in the respiratory epithelium of affected patients during the SARS-CoV pandemic, where it was associated with progressive damage to lung and heart tissues [19–22]. This evidence concerns the gene TMPRSS2 and COVID-19.