The deduced amino acid sequence comparison and hydrophobicity profiles of the gp4 proteins between the 7 isolates and reference viruses. Deduced amino acid sequence comparison of the gp4 proteins between the 7 isolates from China (GenBank accession no. EU017512, EU177105, EU177110, EU177119, EU177113, EU255926 and EU366150) and another Chinese isolates (BJ-4) (GenBank accession no. AF331831), VR2332 (GenBank accession no. EF536003) and MLV (GenBank accession no. AF159149) available in GenBank. Only the amino acids different from those in the consensus sequence are indicated. The black boxed residues indicate the difference AA position sites.