Increased ACE2 levels in the blood of patients with COVID-19 have already been described by several studies using ELISA as well as mass spectrometry-based assays (Fagyas et al., 2021; Gerard et al., 2021; Lundstrom et al., 2021; Patel et al., 2021; Reindl-Schwaighofer et al., 2021; Wang et al., 2021)., and were higher in more severely ill patients (Fagyas et al., 2021; Patel et al., 2021; Reindl-Schwaighofer et al., 2021). This evidence concerns the gene ACE2 and COVID-19.