2 million FACS-sorted cells were crosslinked with 1% formaldehyde at room temperature for 10 minutes. Crosslinking was terminated by addition of 0.125M glycine and washed with ice-cold PBS containing protease inhibitor cocktail (PIC, Roche). Samples were sonicated to 200-500bp fragments for 8 cycles at 5 minutes each (Biorupter, Diagenode). Sheared chromatin were incubated with antibodies and Protein A (Dynabeads, Invitrogen). Antibodies used were against H3K27ac (ab4729; Abcam), H3K4me1 (ab8895; Abcam). Chromatin were reverse crosslinked at 68°C for 3 hours at mixed in Elution buffer (1M Tris pH 7.5, 0.5M EDTA, 5M NaCl, 10% SDS, Proteinase K) at 1100rpm. DNA was purified by MiniElute PCR Purification Kit (Qiagen) and eluted in 22μL EB buffer. Purified DNA was used to generate libraries with the ThruPLEX-FD preparation kit (Rubicon)