HDAC9 and juvenile Huntington disease: We report for the first time that prolonged subcutaneous administrations of 106, 109 and 136 are all well tolerated in mice at the tested doses, concurring with a recent long-term study of the related HDAC inhibitor 4b, which demonstrated amelioration of the Huntington disease phenotype in R6/2 mice without any discernable toxicity (Thomas et al., 2008).