(A) ATAC-seq (n = 2) in HeLa cells cultured at 21% oxygen, transfected with control siRNA and exposed to 0 h (control), 1 h and 24 h 1% oxygen (hypoxia (Hpx)). (B) Overlap of open chromatin regions (ORs). (C) Number of high stringency (log₂ fold change >±0.58 and FDR <0.05) differentially open chromatin regions (DORs) and genes with DORs (DOR genes), and percentage relative to total ORs and OR genes. (D,E) Volcano plots for 1 h hypoxia vs control DOR analysis and 24 h hypoxia vs control DOR analysis, blue points indicate high stringency DORs. (F) Genomic location of DORs. (G) Metagene plots of ATAC-seq signal (RPKM) at the indicated regions.