ACE2 and COVID-19: Furthermore, Osman et al. (2021) observed that while RAS components were modulated in COVID-19 patients, their levels did not consistently correlate with clinical severity [26] and, in a recent study by Kakavandi et al. (2024), the levels of ACE2 and Ang II in SARS-CoV-2 positive and negative subjects were not significantly different [27].