Feline leukemia virus (FeLV) is a retrovirus that infects cats. As a retrovirus, FeLV is transmitted as an RNA virus but the RNA is reverse transcribed into DNA. Retroviruses contradict the Central dogma of molecular biology. FeLV is usually transmitted between infected cats when the transfer of saliva or nasal secretions is involved. If not defeated by the animal's immune system, the virus can be lethal. The disease caused by this virus is a form of cancer of blood cells called lymphocytes (a leukemia).
FLV; FLV gp70