Given that overexpression of PDEF repressed growth of prostate cancer DU-145 cell line and PC-3 cell line, which represents the NEPC cells, and that the expression of PDEF in prostate cancer specimens is downregulated when compared with the controls [22], it suggests that miR-204 is an oncomiR through targeting PDEF and inhibiting PDEF’s tumor-suppressive function in PCa. The gene discussed is SPDEF; the disease is prostate carcinoma.