To further evaluate the correlation between the affinity of chromodomains and their repressive activity, we delivered by lentiviral infection double-domain versions of Cbx-KOX1-dCas9 fusions containing two copies of Cbx3.VD, Cbx5.VD, or Cbx7.VD arranged in tandem and compared their repressive potential to single-domain high-affinity chromodomain fusions (Fig. 4d). Here, CBX1 is linked to infection.