The tissues were homogenized in 20 ml lysis buffer (100mM NaCl, 20mM Tris, 10mM EDTA, 0.5% SDS) with 200 μl of 20 mg/ml Proteinase K (Life Technologies, AM2544). Homogenized tissues were incubated at 55°C overnight.  Genomic DNA was extracted with phenol-chloroform (ThermoFisher Scientific, 15593049) or the Qiagen Puregene Kit (Qiagen, 158063) and precipitated with ethanol. Plasmid DNA extraction was performed following QIAGEN Plasmid Plus Midi Kit instructions Custom Tuba-seqUltra library construction protocol. For detailed methodology, please refer to the "Tuba-seqUltra library preparation" section in the Methods of the manuscript "Functional mapping of epigenomic regulators uncovers coordinated tumor suppression by the HBO1 and MLL1 complexes," available at: https://www.biorxiv.org/content/10.1101/2024.08.19.607671v1