ACE2 and COVID-19: Monoclonal antibodies against SARS-CoV-2, some of which were derived from COVID-19 patients’ B-cells, were found to neutralize the virus in cultured cells (Wang C. et al., 2020; Andreano et al., 2021) and a study using a transgenic mouse model bearing human ACE2 confirmed that specific monoclonal antibodies can reduce virus titers in infected lungs (Wu et al., 2020).