These experiments should demonstrate the effectiveness of CD117+ stem cell mobilization from the bone marrow to the peripheral blood (PB) via CXCR4 antagonism (Plerixafor) and whether end-stage lung disease affects the ability to mobilize stem cells. Additionally, these results will be used to mathematically extrapolate approximately how many rounds of peripheral blood apheresis will be required to attain adequate stem cell numbers for clinical infusion (10e7) for a future study.