To see if sialic acid mediated CCoV-HuPn-2018pp entry into those human cell lines, we first used neuraminidase from Vibrio cholerae or Arthrobacter ureafaciens to remove sialic acid from the surface of Huh7 cells, or APN and ACE2 cotransfected 293T cells, followed by infection with pseudotyped viruses. This evidence concerns the gene ACE2 and infection.