ACE2 and COVID-19: Conclusively, regarding primary sites of SARS-CoV-2 infection although lungs (Fig. 2a) and likely the gastrointestinal tract (Fig. 2b) are grounds zero during the infection process, SARS-CoV-2 and/or COVID-19 also tear multiple organ systems, with major targets (because of high ACE2, TMPRSS2 expression) being the heart and kidneys.