Stem cells will be collected from both the patient and donor. To do this, the hormone G-CSF will be injected under the skin for several days to push stem cells out of the bone marrow into the bloodstream. Then, the stem cells will be collected by apheresis. In this procedure the blood is drawn through a needle placed in one arm and pumped into a machine where the required cells are separated out and removed. The rest of the blood is returned through a needle in the other arm.