library_construction_protocol: Cerebellar tissues were processed for ChIP using Ren lab's protocol from Roadmap Epigenome (https://www.encodeproject.org). Library preparation on samples was conducted using manufacturer's protocols for NEBNext Ultra II Dna Library Prep Kit (New England BioLabs, CAT#E7645) and NEB Multiplex Dual Index oligos (New England BioLabs, CAT#E7600, #E7780) with the following modifications. We input approximately 10ng of sample for half reactions, we diluted the NEBNext Illumina adaptor 1:25, we used the following PCR cycling conditions: 1 cycle of Initial Denaturation at 98C for 30 seconds, 12+ cycles of Denaturation at 98C for 10 seconds then Annealing/Extension at 65C for 10 seconds, and 1 final cycle of extension at 65C for 5 minutes. Following library preparation, double size selection was performed using Ampure beads and quality and concentration of libraries were determined by an Agilent 4200 Tapestation with High-Sensitivity D1000 reagents before pooling for sequencing.