Based on the hypothesis that chromatin structure and the histone modification state of the FXN gene are responsible for gene repression on alleles containing expanded GAA•TTC repeats, our lab found that a commercially available histone deacetylase inhibitor (BML-210, Figure 1) and derivatives 4b, 106 and 109 that we synthesized (Figure 1) relieve repression of the FXN gene in lymphoid cell lines derived from FRDA patients, in primary lymphocytes from donor FRDA patient blood [4-6], and in mouse models [7-9]. Here, FXN is linked to Friedreich ataxia.