Cells we fixed in 1% formaldehyde at RT for 10 minutes, nuclei extracted and chromatin sonicated using a bioruptor (10 cycles, 30s on 30s off). Cleared chromatin was incubated with anti-RBP1 antibody (Active Motif, 39097). Input DNA serves as negative control for antibody enrichment. Libraries were prepared using the NEB Next Ultra 2 kit.