SPHK1 and Familial prostate cancer: Recently, we found SPHK1 promotes prostate cancer metastasis and neuroendocrine prostate cancer (NEPC) development in which FTY720 (Fingolimod), an FDA-approved SPHK1 inhibitor for multiple sclerosis, exhibits significant therapeutic efficacy using pre-clinical NEPC xenograft models [24, 41, 42].