EBER refers to two short small nuclear RNAs

Non-coding RNA

A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...

 associated with the Epstein-Barr virus

Epstein-Barr virus

The Epstein–Barr virus , also called human herpesvirus 4 , is a virus of the herpes family and is one of the most common viruses in humans. It is best known as the cause of infectious mononucleosis...

.

EBER1 and EBER2 are 167 and 172 nucleotide

Nucleotide

Nucleotides are molecules that, when joined together, make up the structural units of RNA and DNA. In addition, nucleotides participate in cellular signaling , and are incorporated into important cofactors of enzymatic reactions...

s in length respectively. They are not required for EBV-mediated growth transformation. These two RNAs are transcribed

Transcription (genetics)

Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

 by the host's RNA polymerase III

RNA polymerase III

RNA polymerase III transcribes DNA to synthesize ribosomal 5S rRNA, tRNA and other small RNAs. The genes transcribed by RNA Pol III fall in the category of "housekeeping" genes whose expression is required in all cell types and most environmental conditions...

 even during a latent infection of EBV. EBER1 associates with human ribosomal protein L22 and causes this protein to move from the nucleolus

Nucleolus

The nucleolus is a non-membrane bound structure composed of proteins and nucleic acids found within the nucleus. Ribosomal RNA is transcribed and assembled within the nucleolus...

 to the nucleoplasm

Nucleoplasm

Similar to the cytoplasm of a cell, the nucleus contains nucleoplasm or karyoplasm. The nucleoplasm is one of the types of protoplasm, and it is enveloped by the nuclear membrane or nuclear envelope. The nucleoplasm is a highly viscous liquid that surrounds the chromosomes and nucleoli...

.

EBERs 1 and 2 can be deleted from the viral genome

Genome

In modern molecular biology and genetics, the genome is the entirety of an organism's hereditary information. It is encoded either in DNA or, for many types of virus, in RNA. The genome includes both the genes and the non-coding sequences of the DNA/RNA....

 without noticeable phenotypic

Phenotype

A phenotype is an organism's observable characteristics or traits: such as its morphology, development, biochemical or physiological properties, behavior, and products of behavior...

 changes, though this has never been found deleted in nature. EBER expression alone can induce tumours in severe combined immunodificient mice.