The evolving role of umbilical cord blood in transplantation, immunotherapy, and regenerative medicine: a brief contemporary review by the ISCT lab practices committee.

Umbilical cord blood (UCB) is a rich source of hematopoietic stem and progenitor cells (HSPCs), mesenchymal stromal cells (MSCs), and diverse immune cell subsets with unique developmental and functional properties. These characteristics have established UCB as an important graft source for hematopoietic stem cell transplantation (HSCT) and an emerging platform for next-generation immunotherapies and regenerative applications. Importantly, cord blood transplantation remains most widely used in pediatric patients, who constitute the majority of UCB transplant recipients due to favorable tissue compatibility and hematopoietic reconstitution kinetics and the suitability of single-unit UCB grafts. Advances in donor recruitment, processing, cryopreservation, ex vivo expansion, and cell engineering continue to broaden the clinical utility of UCB while addressing historical limitations related to cell dose and engraftment kinetics. This review summarizes current biological insights, key aspects of banking infrastructure and the regulatory landscape, established and investigational therapeutic uses, and the evolving challenges and opportunities that will shape the future integration of UCB usage beyond graft source for HSCT.