 These cells take root in the person's bone marrow, replicating and creating cells that mature and create normally functioning adenosine deaminase protein, resolving the problem.As of April 2016, the transduced cells had a shelf life of about six hours.Prior to extraction, the person is treated with granulocyte colony-stimulating factor in order to increase the number of stem cells and improve the harvest; after that but prior to reinfusion, the person is treated with busulfan or melphalan to kill as many of the person's existing HSCs to increase the chances of the new cells' survival.