Reticuloendotheliosis Viruses, Avian

**Definition:** A group of viruses in the genus GAMMARETROVIRUS comprising a few isolates from birds, with no known corresponding endogenous relatives.

**Tree numbers:** - B04.613.807.375.700 - B04.820.650.375.700

**Synonyms:** - Avian Reticuloendotheliosis Viruses - Avian Reticuloendotheliosis Virus Group