CD44 and prostate carcinoma: Treatment of prostate cancer cells with CXCL12 at a concentration of 100 ng/ml induced activation of the PI3K/AKT pathway (up to 1.5–2.0 fold increase in AKT phosphorylation in PC3 and DU145 cells, respectively) (Figure 4B), in addition to increasing the CD44+/CD133+ population for both PC3 and DU145 cells (Figure 2D).