As a host receptor of SARS-CoV-2, the expression level of angiotensin-converting enzyme 2 (ACE2) has been found to influence both the risk and severity of infection (Hoffmann et al., 2020; Wrapp et al., 2020; Zhou et al., 2020a; Li et al., 2003; Li et al., 2005). Here, ACE2 is linked to infection.