Rac1 targeting impairs p53-deficient tumor growth in vivo. (A) BL41 cells were transduced with either a YFP-tagged shRac1 construct or scrambled sh control (shSCR) and sorted as in Figure 4A. Cells were harvested 24 hours after sorting and injected (2 × 10⁶) contralaterally into the flanks of NOG mice and tumor growth was monitored. (B) Tumors from panel A were excised and weighed at day 73. Error bars represent SD.