The biology of Epstein–Barr virus (EBV) is fascinating even to the casual observer. To a devotee like me, it is positively gripping. The virus has a variety of remarkable potentials, including the ability to cause normal lymphocytes to grow indefinitely in a test tube, a process called immortalization. A related phenomenon, polyclonal-growth stimulation of B lymphocytes, underlies the pathogenesis of infectious mononucleosis and the diffuse lymphomas that occur in immunodeficient patients. Such B-cell stimulation is also a likely initiating event in virus-associated cases of Burkitt lymphoma.1 The virus residing in an immortalized lymphocyte is latent. That is, mature virus is . . .