As alveolar hyperplasia was observed in severe COVID-19 histology57, it is reasonable to assume that SARS-Cov-2 promotes abnormalities in the KKS, RAS and CS that are least partly derived from a reactional increase in alveolar type 1 precursors which produce serum KKS elements, and a decrease in terminally differentiated ACE2high alveolar type 1 cells, responsible for ultimately inhibiting the KKS through ACE2 activity. The gene discussed is ACE2; the disease is COVID-19.