ACE2 and COVID-19: COVID-19 is the subject of intense research, with potential therapeutic drugs in various stages of testing, and with as many new therapeutic targets being investigated, such as the SSAA09E2 and CP-1 peptide that interfere with ACE2 recognition, and camostat and nafamostat that inhibit the type 2 transmembrane serine protease (TMPRSS2) [27].