EBV episome, transcripts, mRNAs, and proteins in type III latent infection. Largely unique (U1-U5) and highly repetitive internal (IR1-4) or terminal repeat (TR) DNA domains, the episomal replicon (ori P), and the location of exons encoding EBV nuclear proteins (EBNA 1, 2, 3A, 3B, 3C, and LP) or membrane proteins (LMP 1, 2A, or 2B) genes are indicated. (Source: Ref.12)