SPOP and Familial prostate cancer: To test this hypothesis, we generated a series of Myc-tagged prostate cancer-associated mutants of SPOP, including Y87C, Y87N, F102C, S119 N, F125 V, K129E, W131G, W131C, F133 L, F133 V and K134 N, and examined their capacity to promote ATF2 degradation.