HDAC9 and metastatic prostate carcinoma: Wong et al. showed that P-REX1 expression in prostate epithelial cells could be stimulated by a HDAC inhibitor, and suggested that disassociation of HDACs from the transcription factor Sp1 on the PREX1 promoter may contribute to aberrant P-REX1 upregulation in metastatic prostate cancer [40].