DPP4 and infection: Of note, MERS-CoV can only initiate infection via the use of species-restricted orthologs of DPP4, including those from humans, rabbits, bats, horses, and camels.13 Emerging evidence has confirmed that angiotensin converting enzyme 2 (ACE2) is also the host cellular receptor employed by SARS-CoV-2; this finding is not surprising given the nucleotide sequence homology reported in comparison between SARS-CoV-2 and SARS.14–17