Analysis of survival of HW80 hosts from experiments 2 and 3 receiving transplants of wild-type, STAT5ab^-/-, or c-Mpl^-/- BM cells. For quaternary transplantations resulting from experiments 2 and 3, the survival of mice was not 100%. Shown are the results of daily monitoring of survival for mice from the quaternary transplantations. The percentage of survival (y-axis) is plotted against the number of days since injection into lethally irradiated quaternary hosts.