Cotreatment with R115777 and UCN-01 results in marked tumor growth suppression in a murine xenograft model of MM.1S cells. (A,B) Nude mice were inoculated subcutaneously with 10⁷ MM.1S cells into the right rear flank. After tumors were measurable, 25 mg/kg R115777 with or without 0.5 mg/kg UCN-01 were administrated intraperitoneally daily for 12 days. Tumor size was monitored every 2 days during drug treatment (days 1-12; panel A) and for an additional 12 days after cessation of drug treatment (days 13-24; panel B). Mean tumor volumes are shown (n = 9 per group).