PROS1 and infection: Sun et al. analyzed the integrin recognition sequences of PEDV S proteins and found four conserved integrin recognition amino acid motifs (Asp-Gly-Glu, Lys-Gly-Glu, Arg-Leu-Asp, and Leu-Asp-Val) in the S proteins of various PEDV strains, suggesting that integrin proteins may act as infection-related proteins for the attachment and entry of PEDV [134].