HDAC4 and neoplasm: In MM cells, ectopic miR-29b was shown to downregulate major tumor promoting or anti-apoptotic mRNA targets, including CDK6, MCL-1, SP1 [14], as well as mRNAs coding for epigenetic regulators, such as HDAC4 [19] and DNMT3A/B [20], thus triggering cell cycle arrest and apotosis.