title: ATAC-seq of Homo sapiens : A549
design: ATAC-seq was performed as previously described 19,20. 5104 A549 cells were collected and washed with cold PBS and then re-suspended in resuspension buffer (10 mM Tris-HCl, pH 7.4, 10 mM NaCl, 3 mM MgCl2).  After lysed in lysis buffer (10 mM Tris-HCl, pH 7.4, 10 mM NaCl, 3 mM MgCl2, 0.1% NP-40), nuclei were collected and incubated in transposition mix containing Tn5 transposase (Illumina, #15027865) for 30 minutes at 37C. The DNA fragment was purified using the QIAGEN MinElute PCR Purification Kit and ligated with adapters, and subsequently amplified by PCR using as described previously20. Finally, the products were sequenced using Illumina NovaSeqTM 6000.