MKI67 and Epstein-Barr virus infection: To investigate the immunophenotypic effects of EBV infection on B-cell during early infection, we analyzed the expression profile of several B-cell activation and proliferation surface antigen markers (CD5, CD10, CD23, CD39, CD40, and CD44) as well as the intracellular proliferation marker (Ki-67) at different times post-infection.