USP7 and Epstein-Barr virus infection: EBNA1 appears to be constitutively bound to oriP elements in latent EBV infections in proliferating cells [37],[38] and, in these cases, the functional relevance of these observations for oriP-related functions most likely lies in the ability of USP7 to form a ternary complex with DNA-bound EBNA1, as verified at the FR element in EBV-infected cells.