ACE2 and influenza: After reviewing the full texts of 938 articles, 71 COVID-19 studies were included in the meta-analysis (Figure 1A).1, -3,13,27, , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , -94 Similarly, 7742 articles on ACE2-associated (SARS-CoV-1, influenza H1N1, H7N9) and non-ACE2-associated viruses (MERS-CoV, other influenza strains) were screened based on their titles and abstracts and 6841 articles were excluded.