Treatment with 25A destroys in vivo clonogenic B-precursor ALL xenograft cells. Xenograft cells isolated from the spleens of leukemic NOD/SCID mice were treated with 25A (lipid concentration: 162 µg/mL; C61 concentration: 30 µg/mL) or 25B (lipid concentration: 162 µg/mL; C61 concentration: 0 µg/mL), or were left untreated (Tx) for 48 hours at 37°C and then reinjected into NOD/SCID mice (2 mice per group per case, 10 mice per group for all 5 cases combined). The starting cell number was identical for each treatment condition, and all mice in a given xenograft case received the same volume of cells with the same starting cell number in the inoculum. The untreated control inoculation samples in the 5 cases contained 200 000 to 400 000 cells. Experiments were terminated by the euthanasia of all mice in all treatment groups as soon as control mice showed signs of morbidity. The actual times to termination in the 5 independent experiments were 20 days, 25 days, 91 days, 112 days, and 123 days after leukemic cell inoculation. In each of the 5 independent experiments, NOD/SCID mice that were challenged with untreated or 25B-treated xenograft cells rapidly developed overt leukemia with massive splenomegaly and multiorgan infiltration. By contrast, the spleens of mice that were challenged with 25A-treated xenograft cells were much smaller and no multiorgan involvement was observed in any of the 3 cases examined histopathologically. (A-B) depict the spleens of mice from 2 representative experiments. The spleen images were obtained using an iPhone 4S equipped with an 8-megapixel iSight camera (Apple, Cupertino, CA). The cumulative data are shown in (C-D). The statistical comparisons as well as organ infiltration data are shown in (E). BM, bone marrow; BR, brain; KD, kidneys; LIV, liver.