ACE2 and infection: Expression of ACE2 and TMPRSS2 in these cells is indicative of potential sites of infection for SARS-CoV-2, validated experimentally using cell lines and organoid models of cells of different subtypes of tissues, including the brain, colon, gut, ileum, liver, lung, eye, and kidney, and also in animal models, as shown in Figure 5 [67,68,69,70,71,72,73,74,75,76,77].