CTCF and Facioscapulohumeral dystrophy: Interestingly, the function of ZF9 (together with ZF10 and ZF11) enables CTCF to recognize different DNA sequences across the genome and to promote transcriptional insulation that has been previously described in the pathophysiology of FSHD (Ottaviani et al., 2009; Yin et al., 2017; Xu et al., 2018; Huang et al., 2021).