A better characterization of cell sorts used in all the abovementioned studies will help in the fitting selection of cell to be utilized. If the cells require in vitro expansion earlier than transplantation stays to be clarified. To notice, two clinical studies92,ninety three used part of or entire AUCB. Eventually cellular senescence and life span need more clarification. Senescence of cultured stem cells is another major concern for clinical trials. Prolonged in vitro enlargement might set off senescence phenotype and telomere shortening, in this manner the stem cell regenerative capability could possibly be modified.54