ding, the virus must gain access to host cytosol, which is accomplished by acid-dependent proteolytic cleavage of the S protein by cellular serine protease TMPRSS2, which is similar to S protein priming in SARS-CoV (14) (Figure 2 ).
Figure 2 Proposed Mechanism of Entry for SARS-CoV-2 Via ACE2
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) binds to the catalytic site of ACE2 via its S protein. To gain access to the host cy