Anti-ACE2 completely inhibited SARS-CoV-2 MLV PPs infection of the HEK293T-ACE2 cells at 10 μg/mL (S2D Fig), but had no enhancing, nor inhibiting effect on CB6-induced cell-cell fusion on spike-expressing HEK293T control cells (S2E Fig, top). Here, ACE2 is linked to infection.