| hepatitis b virus | species | viruses and viroids | viruses | species | 10407 |
| human endogenous retrovirus | species | viruses and viroids | viruses | species | 11827 |
| human immunodeficiency virus 1 | species | viruses and viroids | viruses | species | 11676 |
| human immunodeficiency virus 2 | species | viruses and viroids | viruses | species | 11709 |
| human t-lymphotropic virus 2 | no rank | viruses and viroids | viruses | no rank | 11909 |
| macaque simian foamy virus | species | viruses and viroids | viruses | species | 338478 |
| mason-pfizer monkey virus | species | viruses and viroids | viruses | species | 11855 |
| murine leukemia virus | species | viruses and viroids | viruses | species | 11786 |
| primate t-lymphotropic virus 1 | species | viruses and viroids | viruses | species | 194440 |
| rhesus macaque simian foamy virus | species | | | species | 2170199 |