library_construction_protocol: For all samples, 1x105 cells were washed in PBS and pelleted. The cell pellet was resuspended in 100μL freezing medium, composed of 10% dimethyl sulfoxide (Sigma, St. Louis, MO, USA) and 90% FBS (Sigma, St. Louis, MO, USA). Then, it was stored at -80°C prior to shipment to CD Genomics. Nextera kit