Activation of Akt after stimulation with CXCL12 is inhibited by PIK-90 and PI-103. After preincubation with the PI3K inhibitors that are indicated above the bands, CLL B cells were stimulated with CXCL12 for 1 minute and then lysed. The phosphorylated forms of Akt (p473; p308 not shown) were visualized by Western blot, and the band intensities were analyzed using the Software LabImage 1D. The relative band intensities compared with the band intensity of the control sample (+CXCL12, no PI3K inhibitor, 100%) are indicated below each band. PIK-90 and PI-103 reduced the p473 phosphorylation of Akt by approximately 50% compared with the control. In contrast, the inhibitory effects of TGX115 and Ly294002 on CXCL12-induced Akt phosphorylation were minor. The figure shows data from 1 representative patient sample of 3 patient samples with similar results.