FXN and Friedreich ataxia: In agreement with this, we observed genes related to apoptosis were up-regulated after Fxn knockdown in FRDAkd mice heart (Figure 7d), which has been previously associated with FRDA pathogenesis and reported in other Fxn deficiency models (Simon et al., 2004; Huang et al., 2009; Bolinches-Amorós et al., 2014).