PMAIP1 and pancreatic neoplasm: Class I HDACs are important regulators of apoptosis and cell cycle, e.g., HDAC2 induces epigenetic silencing of the pro-apoptotic NOXA gene, whereas HDAC2 inhibition sensitized pancreatic tumor cells for tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis [18,39].