Persistence of the losing cord blood unit following double cord blood transplantation: finding the unseen

To the editor: Double cord blood (CB) transplantation (dCBT) is an accepted treatment of patients with hematologic malignancies.[1][1],[2][2] In the vast majority of dCBT recipients, 1 unit emerges as the sole source of long-term hematopoiesis.[3][3] As measured by standard clinical testing for