P53 activates the transcription of genes involved in cell cycle arrest, DNA repair, and apoptosis. Deletion and point mutation at the TP53 locus occur in 25%-40% and 5%-40% of prostate cancer, respectively. Although the frequency of p53 mutations seems to be lower in prostate cancer than in other cancers, these alterations are not exclusively late events, as they have been shown in 25% to 30% of clinically localized prostate cancer. Several studies indicate that p53 overexpression may be associated with poor prognosis, especially when present in combination with Bcl2. Interestingly, SPOP mutations are also mutually exclusive with deletions and mutations in the TP53 tumor suppressor.