ACE2 and acute kidney injury: AKI frequencies did not differ between virus groups in critically ill patients: COVID-19 51% (95% confidence interval [CI]: 44%-57%), ACE2-associated respiratory viruses 56% (95% CI: 37%-74%, P = .610), and non-ACE2-associated viruses 63% (95% CI: 43%-79%, P = .255) or between ACE2-associated respiratory viruses and non-ACE2-associated viruses (P = .624) (Figure 2).