Phylogenetic tree generated by NEIGHBOR program in the PHYLIP package for NS5B and core amino acid sequences. Genetic distance was calculated with PRODIST program from the PHYLIP package based on Kimura's distance. A bootstrap analysis using 100 bootstrap replicates was performed to assess the reliability of each branch point. Bootstrap values greater than 70% are shown. The corresponding genetic distances are also shown. The arc signifies the sequences generated from HC9A98987. The dashed line reflects a genetic distance of 0.29 between AY587845 (2k/1b) and AB031663 (2k).