the root (no rank)
Viruses (domain)
retroid viruses (subkingdom)
Retroviridae (family)
Orthoretrovirinae (subfamily)
Deltaretrovirus (genus)
[hide inferior taxa]
bovine leukemia virus (species)
human T-cell lymphotropic virus type 1 (species)
human T-cell lymphotropic virus type 2 (species)
human T-lymphotropic virus 4 (species)
primate T-lymphotropic virus 1 (species)
primate T-lymphotropic virus 2 (species)
primate T-lymphotropic virus 3 (species)