ACE2 and infection: The ACE2–CRFK cells were infected by both LpVspike(+) and LpVspike(−) in the presence of Deax, whereas infection only occurred in the ACE2–CRFK line with LpVspike(+) infection (1 × 104 RLU with 50 μL of viral solution) in the absence of Deax.