ACE2 is a major link in the pathogenesis of COVID-19 and has two major biological functions in this context: (1) it catalyzes the conversion of Ang I and Ang II to Ang 1–9 and Ang 1–7, respectively, which leads to organ protection, and (2) serves as the receptor for the entry of SARS-CoV-2 into cells [9]. Here, ACE2 is linked to COVID-19.