ACE2 and infection: However, the ACE2–Ang (1–7)–Mas branch of the RAS serves as a negative regulator of the system that counters ACE–Ang II–AT1R branch activities (Kuba et al., 2013); therefore, as ACEi and ARB were shown to upregulate ACE2 (Kriszta et al., 2021; Parit & Jayavel, 2021), thereby modifying the balance between the canonical and noncanonical axes of the RAS, concerns have been raised over a potential negative impact of ACEi/ARB treatments on immune responses to pathogen infection.