To further clarify the anti-tumor mechanism of DOT1L inhibition in HER2-positive breast cancer cells, we performed Single-cell Assay for Transposase-Accessible Chromatin sequencing (scATAC-seq) analysis in SKBR3 cells treated with DMSO, SGC0946 or EPZ-5676 for 6 to 12 days (Supplementary Fig. S13). Here, ERBB2 is linked to breast cancer.