TMPRSS2 and viral load: Several miRNAs, including miR-200b-3p, miR-214-3p, miR-200c-3p, miR-125b, miR-18, miR-98-5p, and miR-27b, have been identified as targeting ACE2, TMPRSS2, or other bioactive molecules involved in the pathological processes of COVID-19 and other viral diseases.