Indomethacin delays progression of REH in vivo. Xenograft REH mice (5 mice per treatment group) were treated with indomethacin or vehicle as described in “Materials and methods." (A) Progression of leukemia was followed by noninvasive in vivo imaging of luminescence from the mice. The images were taken between 1 and 4 weeks after IT injection as indicated. (B) Xenograft luciferase activity (photons per second [p/s]) from the xenografts presented in panel A measured relative to week 1 after IT injection. Data represent the mean ± standard error of the mean, n = 5, *P < .05 (unpaired Student t test).