Autologous bone marrow transplantation in two baboons. Before infusion, bone marrow cells were treated with anti-VLA4 antibody, the cells were infused without washing, and blood samples were taken at various points thereafter to evaluate blood counts and circulating clonogenic progenitors. Note that prompt engraftment occurred in both animals compared with historical controls. (One of the animals later died from a presumed viral infection, whereas the other animal remained healthy beyond 2 years from transplantation.)