Efficacy of rapamycin in xenograft models of Ph-like ALL. Genetic lesions are indicated to the left of each row. (A) Peripheral blast count (PBC) over time in ALL xenografts. Graphed are means and SDs with PBC × 10³ per microliter on the vertical axis and weeks of treatment on the horizontal axis; n indicated in panel B. (B) Splenic blast count (SBC) at sacrifice. Means and SDs are graphed with the vertical axis representing absolute SBC × 10⁶; n for each arm indicated above bar. (C) Levels of phosphorylated ribosomal protein S6 (pS6) by immunoblot. Xenografts were treated with rapamycin (rap) or vehicle (veh) for 72 hours, spleens were harvested, and protein lysates subjected to immunoblot for pS6, total S6, and actin.