SPHK1 and prostate cancer: Balanocarpol induced down-regulation of SphK1 activity and expression in prostate cancer cells, the mechanism may involve changes in the SphK1 protein turnover, as has been shown for other SphK1 inhibitors to induce ubiquitin proteasomal degradation of SphK1 or changes in gene promoter activity (Loveridge et al., 2010).