HDAC9 and neoplasm: The present study addresses the hypothesis that epigenetic treatment of PCC/PGL cell and tumor models with the HDAC inhibitor valproic acid (VPA) and the DNMT inhibitor 5-Aza-2'-deoxycytidine (DAC) is associated with (1) up-regulation of SSTR2, (2) increased uptake of radiolabeled somatostatin analogs, and (3) neo-adjuvant effects in combination with PRRT.