HDAC9 and Friedreich ataxia: An elevated level of miR-886-3p in FRDA is associated with the downregulation of the FXN gene and the use of anti-miR-886-3p or the HDAC inhibitor 4b alone has been shown to partially reverse FXN gene repression by reducing miR-886-3p levels (Mahishi et al., 2012; Bandiera et al., 2013).