Phylogenetic analysis of anogenital HPV types . Branches determined by 100 bootstrap estimations using each of the methods in the following order: Bayesian credibility value, parsimony bootstrap percentage based on nucleotide alignment, and parsimony bootstrap percentage based on amino acid alignment. All definitely, probably, and possibly carcinogenic HPV types belong to one phylogenetic clade of the alpha genus.
Schiffman et al. Infectious Agents and Cancer 2009 4:8 doi:10.1186/1750-9378-4-8