CD34 and Epstein-Barr virus infection: The failure to do so may reflect the relative paucity of some aspects of the intact host immune response in this CD34-depleted cord blood model (e.g., NK cells), the absence of EBV-specific memory T cells at the initiation of EBV infection, and the fact that EBV is a highly transforming virus that has many mechanisms for dampening the host immune response.