CD4 and Facioscapulohumeral dystrophy: The protocol we followed is described in Figure 3A. Briefly, immortalized FSHD cells were transfected with the TALEN pair 406/407, single-stranded DNA donor oligonucleotides (including a miR1) and a CD4-expressing plasmid for the selection of the transfected cells using magnetic beads coupled to anti-CD4 antibodies (MACS column).