Cytomegalovirus can remain latent for long periods in a person with a healthy immune system, but can be reactivated in someone who is immunocompromised, such as in a patient who undergoes allogeneic hematopoietic cell transplantation (HCT). After decades of scientific stagnancy, newly approved treatments and ongoing phase 3 trials could rewrite the rules for management of cytomegalovirus (CMV), experts said.