The knock-in mice
The knock-in mice. including severe acute respiratory syndrome (SARS),1 Middle East respiratory syndrome (MERS)2, and coronavirus disease 2019 (COVID-19).3,4 One of the challenges to control coronaviruses is that they evolve constantly, even though slower than HIV and influenza.5 Analyses of over 28,000 gene sequences of SARS-CoV-2 spike protein (S-protein) in May 2020 exposed a D614G…