Subsequently, changes to ACE2 expression during viral infection can lead to an imbalance in renin-angiotensin system (RAS) signaling contributing to the manifestation of clinical symptoms such as excessive inflammation (Mahmudpour et al., 2020), myocardial injury (Clerkin et al., 2020), and lung injury (Ni et al., 2020b). Here, REN is linked to viral infectious disease.