2.9. CUT&Tag assay

CUT&Tag was performed using 1 million cells, as previously reported [35]. Primary antibodies used were anti-H4R3me2s or anti-H3R8me2s. The secondary antibody was goat anti-rabbit IgG (AS070; ABclonal, Wuhan, China) at a dilution of 1:100. Total DNA was extracted and subjected to PCR. The following primers were used to amplify the indicated region surrounding the transcription start sites of Pik3ca: (forward 5′-CCTCAGTTTCAGGTTCCCCA-3′ and reverse 5′-GCGGGTACAGAAGCAAGAAG-3′). All experiments were repeated thrice independently, and the obtained data were normalized to that of the IgG control.