Characterization of the mouse xenograft model of APL. (A) The survival of mice (n = 15) was monitored between days 0 and 31. One mouse died on day 29, and 5 mice died on day 31. (B) Luciferase expression in NB4 cells in mice was measured on days 14, 21, 24, and 28. Five representative mice are shown. (C) Leukemic cells were identified in whole blood smears. A normal neutrophil is marked with a white arrowhead, and a leukemic cell is marked with a yellow arrowhead; scale bar, 50 μm.