ACE2 and infection: Pre-pandemic, pre-clinical observations on the SARS virus showed that ACE2 mRNA abundance was downregulated in infected mouse lungs, that the spike protein down-regulated surface ACE2, that experimental, acid-induced, lung injury was augmented with infection and, notably, that lung tissue ANGII content increased in vivo with experimental injury, which was attenuated by ANGII-AT1R blocker that reduced edema and degree of injury [87].