ACE2 and COVID-19: COVID-19 also links to the RAAS because the spike protein on the surface of SARS-CoV-2 binds near the active site of Ace2, a cell-surface monocarboxy peptidase, allowing infection (Gallagher and Buchmeier, 2001; Hoffmann et al., 2020; Millet and Whittaker, 2015; Simmons et al., 2013; Walls et al., 2020; Yan et al., 2020a).