CASP9 and prostate cancer: Western analysis of ShControl, ShGSK3α and ShGSK3β revealed that silencing GSK3α, but not GSK3β results in increased expression of pro-apoptotic cleaved caspase-9 and cleaved caspase-3 in all the three prostate cancer cell lines (Figure 7A and B), thus indicating the GSK3α is directly involved in the intrinsic pro-survival pathway in prostate cancer cells.