- The only domain which distinguishes Epstein-Barr virus latent membrane protein 2A (LMP2A) from LMP2B is dispensable for lymphocyte infection and growth transformation in vitro; LMP2A is therefore nonessential. Longnecker, R., Miller, C.L., Miao, X.Q., Marchini, A., Kieff, E. J. Virol. (1992)