In FRDAkd mice, immune system activation was among the earliest pathways affected after frataxin knockdown.13 We also observed that several of these target genes including NEDD1, CASP1, CD86, LY9, OMG, CCND2 and CRYM showed differential expression in Friedreich's ataxia patients compared with age- and sex-matched controls. Here, FXN is linked to Friedreich ataxia.