There is no evidence that the banked cells will be viable when thawed and may not be able to be programmed to become the desired cells. Even if they could, would you want cells that have a predisposition to become leukemia cells to be put back in your body? You would be putting cells with the same genetic background that originally caused the disease back into the body. Sure, you would have fewer problems with rejection, but the same problems as the cells which originally caused the disease. A much better bet would be to take donor matched cells from a healthy person and transplant those. I thought about this as a new parent and decided it was not worth the $$ and in general a bad idea. I have a PhD in pharmaceutical chemistry and work for Harvard. We could have afforded the $$, but it is a waste.