An important genetic event found to be associated with progression of prostate cancer is loss of heterozygosity and subsequent homozygous deletion at the 10q23 locus containing the PTEN tumor suppressor gene. PTEN functions, in part, as a negative regulator of the phosphatidylinositol 3' (PI3) kinase - AKT pathway. Targeting the PI3K pathway and/or downstream targets of PI3K has been recognized as an important therapeutic strategy for some time. An important aspect of PI3K signaling is the PTEN mutation and the downstream events associated with PI3K signaling are not mutually exclusive with the aforementioned AR signaling pathway aberrancies that have yielded important therapeutic consequences. Preclinical data has demonstrated that PI3K inhibition upregulates AR expression, but that the net effect is antiproliferative and that concomitant anti androgen therapy is synergistic.