Yes, the virus class identified (murine leukemia virus) is a retrovirus.

The full name of the virus is xenotropic murine leukemia virus-related virus.

While the causes of cancer in cats are unknown, feline leukemia virus is suspected to be a prime contributor.

A widely known preventative of feline leukemia virus is the vaccine which was created in 1969.

Examples are the bovine leukemia virus and the Human T-lymphotropic virus.

The founding member of this family was identified as a gene transduced by the leukemia virus, E26.

Feline leukemia virus causes diverse cancers and other diseases, including immune deficiency.

However, none of the cats infected with the new virus showed evidence of infection by the leukemia virus.

Abl stands for "Abelson", the name of a leukemia virus which carries a similar protein.

Specifically, the vaccine for feline leukemia virus should only be given to kittens and high risk cats.