ACE and COVID-19: ACE’s importance in modulating the immune response can be seen in recent studies showing that lower serum ACE levels are associated with impaired host antiviral response to COVID-19 as well as studies showing increased risk of infection with ACE inhibitor use (Pouwels et al., 2013; Dial et al., 2014; Pouwels et al., 2014; Chen, 2021).