Comparison of the <i>env</i> gene amino acid sequences derived from cluster viruses with subtype B consensus sequence.

<p>35 common mutated positions detected in at least 5 of the cluster viruses are shown in color amino acids. Boxes marked the unusual amino acid whose presence in the cluster is statistically significant when compared with the reference amino acid sequence sets used in the study (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0077663#pone-0077663-t003" target="_blank">Table 3</a>).