50,000 cells were lysed and transpositions were performed using transposase mixture (Nextera DNA library prep kit, Illumina), supplemented with 0.01% digitonin (Promega). Transposition reactions were incubated for 30 min at 37°C in a ThermoMixer with agitation at 300rpm. DNA was purified using the MinElute Reaction Cleanup kit (Qiagen) libraries were amplified using NEBnext PCR master mix with Illumina primers for ATACseq according to Illumina's instructions