Umbilical cord blood stem cellsstem cells collected from the umbilical cord at birth that can produce all of the blood cells in the body (hematopoietic).
Umbilical cord stem cellsHematopoietic stem cells are present in the blood of the umbilical cord during and shortly after delivery.
UndifferentiatedA term used to describe cells or tissues that do not have specialized ("mature") structures or functions.
UnipotentRefers to a cell that can only develop in a specific way to produce a certain end result.
Unipotent stem cellsStem cells that self-renew as well as give rise to a single mature cell type; e.g., spermatogenic stem cells.