XIAP and prostate cancer: Interestingly, we found that STIM1 and ORAI1 promotes the senescence of human prostate cancer cells, as reflected by the aging morphology changes and β-Gal staining in both DU145 and PC3 cells with STIM1 or ORAI1 overexpression and by the overexpression of senescence–related genes, such as DcR2. Also of importance, STIM1 down-regulated the expression of anti-apoptotic proteins, including Bcl-2 and XIAP, which in turn might render the prostate cancer cells more susceptible to apoptotic stimuli.