Additionally, although it is well established that Akt is phosphorylated downstream of CXCL12 signaling in CLL cells [9], it has not been established whether p70S6K, another kinase known to phosphorylate PDCD4 leading to its ubiquitination and degradation, is activated in CLL cells by CXCL12. This evidence concerns the gene AKT1 and B-cell chronic lymphocytic leukemia.