CD34 and cytomegalovirus infection: Even though these results provide relevant insights into the mechanism(s) for how the latent HCMV infection of a minor population of CD34+ HPCs in the bone marrow induces global myelosuppression in HSCT patients, the strict species specificity of HCMV and the lack of surrogate animal models have precluded the in vivo validation of these findings as well as the development of preventive strategies that can target latently infected cells.