To determine whether RepID plays a role in mediating the chromatin association of the cullin proteins, we measured the levels of chromatin-bound cullins in three cancer cell lines (U2OS, HCT116, and K562) in which we depleted RepID (RepID knock-out [KO]) by CRISPR-cas9 gene editing (Supplementary Fig. 1a). Here, CACUL1 is linked to cancer.