of SARS-CoV-2 is cleaved by host proteases into two subunits, S1 and S2 [19]. The S1 subunit binds to the host cell surface receptor angiotensin-converting enzyme 2 (ACE2) for virus attachment, and the S2 subunit fuses the virus and the host cell membrane [19]. The investigation of the effect of CQ on ACE2 in VeroE6 cells showed that effective ant