ACE2 and infection: Given that binding of the SARS-CoV-2 RBD to angiotensin-converting enzyme 2 (ACE2) receptor expressed on host cells facilitates viral entry and subsequent infection, RBD mutations such as N501Y (found on several VOCS including Alpha, Beta, Gamma, and Omicron) can enhance the virus’ binding affinity to ACE2, and boost SARS-CoV-2 infection and transmission [3, 4].