library_construction_protocol: Livers from P15 male C3H/HeOuJ mice were isolated and flash frozen at -80°C. Samples were treated as previously described in Omni-ATAC protocol (Corces et al. 2017), with minor modifications to the nuclear isolation steps (in Step 1, 1 ml of 1× homogeniser buffer was used instead of 2 ml; in Step 4, douncing was performed with 30 strokes instead of 20). ATAC-seq was performed as described previously (Corces et al. 2017).