ACE2 and COVID-19: Here, we hypothesise that an effective anti-COVID-19 preventative or therapeutic intervention should target multiple biochemical networks implicated in virus entry and pathogenesis such as angiotensin-converting enzyme-2 (ACE2)/G protein Mas receptor (MasR) axis, mitogen-activated protein kinase (MAPK) cascade, and toll-like receptor signalling pathways [23].