Easy procurement.
No risk or discomfort to donors.
Low incidence of viral contamination (38.2%) compared to BM (5)
Able to be stored at cryogenic temperatures indefinitely without significantly affecting cell viability.
Immediately available and easily shipped.
There is a high immune tolerance of UCB cells because they are unable to generate cytotoxic T-Lymphocytes, which respond to allogenic antigens. UCB cells are also unable synthesize the proinflammatory cytokines interferon-γ(IFNγ) and tumor necrosis factor-α(TNFα) (58).
UCB has an abundant source (~1% of the mononuclear fraction) of both hematopoietic and nonhematopoietic stem/progenitor cells, which is comparable BM (64,65).
There is a large number of colony forming unit-granulocyte macrophage (CFU-GM) compared to adult sources (10).
Procurement and use are not associated with the same ethical considerations as embryonic and fetal tissues.