Increased osteoblast numbers suppress acute lymphoblastic leukemia. Syngeneic 2-month-old albino C57BL/6 mice were treated orally with LP533401 (200 mg/kg of body weight per day) or vehicle for 15 days and then injected with EL4-GFP-Luc cells. (A) Overall survival of mice treated with LP533401 or vehicle. (B) Whole body luminescence counts assessing leukemia progression. (C) Representative whole body luminescence images. (D) Wright staining of blood smears. Black arrows indicate blasts, blue arrows indicate normal neutrophils, and red arrow indicates lymphocyte. Right panels show inset magnifications of blasts. (E) Percentage of blasts (mean ± standard error of the mean) counted in a total count of 50 cells in peripheral blood smears. (F) Correlation between osteoblast numbers and leukemia tumor burden assessed by luminescence quantification on day 28 (n = 9 mice per group). Overall survival (G) and whole body luminescence counts (H) in syngeneic 2-month-old albino C57BL/6 mice treated orally with LP533401 (200 mg/kg of body weight per day) 1 day following injection with EL4-GFP-Luc cells (n = 10-11 mice per group). *P < .05 vs vehicle-treated mice.