library_construction_protocol: Monocytes were selected following the protocol of the mouse monocyte isolation kit (Miltenyi Biotec, catalog #130-100-629). Briefly, flushed cells were pelleted and resuspended in MACS buffer (phosphate–buffered saline (PBS), pH 7.2, 0.5% bovine serum albumin, 2 mM EDTA). The cells then were incubated with FCR Blocking Reagent and Monocyte Biotin–Antibody Cocktail. After five minutes the cells were rinsed with MACS buffer, pelleted, and resuspended in MACS buffer. The cells were incubated with Anti–Biotin Microbeads for 10 min. After this incubation period the cells were applied to the MACS column in a magnetic field. Flow through was collected as isolated monocytes. The columns were rinsed three times to collect unbound monocyte cells. Collected monocyte cells were counted and volume required for 20,000 cells was calculated. Volumes were pelleted and washed with 50 μl of PBS. After wash cells were pelleted and resuspended in 50 μl of ATAC-Seq Lysis buffer (10 mM Tris-HCl, pH 7.4, 10 mM NaCl, 3 mM MgCl2, 0.1% IGEPAL CA-630) and spun for 10 minutes. Cells were pelleted and resuspended in transposition mixture consisting of 25 μl TD (Illumina catalog #121-1030), 2.5 μl TDE1 (Nextera Tn5 Transposase, Illumina Cat #FC-121-1030) and 22.5 μl nuclease free water and incubated in mixture for 30 minutes. Nextera Tn5 Transposase, Illumina Cat #FC-121-1030 was used for ATAC-library generation