ACE2 of possible SARS-CoV and SARS-CoV-2 intermediate hosts, masked palm civet and Malayan pangolin, respectively, and ACE2 of many mammals including cats, dogs, cows, buffalos, goats and sheep, but not rats (Rattus norvegicus), were predicted to be potentially recognized by SARS-CoV and SARS-CoV-2 [239,240], supporting the finding that rat ACE2 has less efficiency for binding to the SARS-CoV S1 domain and is less susceptible to SARS-CoV S protein-mediated infection [241]. Here, ACE2 is linked to infection.