ATAC-seq was performed as previously described (16 (link)). ATAC libraries were sequenced on an Illumina NextSeq machine (2×75 cycles). The peak sets for ATAC-seq were further analyzed using the deepTools2 suite (v3.3.0)(17 (link)). By using bamCoverage, peaks were normalized to reads per kilobase per million reads normalized read numbers (RPKM).