Overexpression of Rheb2 impairs SDF-1/CXCL12 chemotaxis and CXCR4 expression in 32D cells. (A) Activation of mTOR signaling in response to SDF-1/CXCL12 stimulation in mBM cells, representative of 2 independent experiments. (Bottom panel) Effect of rapamycin at reversing phosphorylation of S6, 100 ng/mL SDF-1/CXCL12 used in this experiment. (B) Transwell chemotaxis of transduced 32D cells to 100 ng/mL SDF-1/CXCL12, combined triplicates from 2 independent experiments. (C) 32D cells, FACS stained for CXCR4 surface expression, combined 2 independent experiments. *P < .02. **P = .05.