Dasatinib induced regression of well-established intracranial K562-pLUC#2 tumors in vivo. On day 9 after tumor implantation, animals with similarly well-established intracranial tumors were randomized into treatment and control sets (n = 8 mice per set) and baseline images were taken (A,C,E). Mice were then treated orally with either 50 or 25 mg/kg of dasatinib daily for 30 consecutive days. On day 20 after tumor implantation, a second set of bioluminescence images were taken (B,D,F). (A,B) Dasatinib treatment, 50 mg/kg. (C,D) Dasatinib treatment, 25 mg/kg. (E,F) Untreated control. Images were set at the same pseudo-color scale to show relative bioluminescent changes over time and signal intensity differences between treatment groups. Dasatinib treatment resulted in complete regression of intracranial tumors to near nondetectable levels, whereas untreated control showed progressive tumor growth with 2 of 8 animals dead on day 20 after tumor implant.