show Abstracthide AbstractAnticancer drug therapy generally elicits the drug tolerance after long-term treatment. Recent studies suggested that 3D chromatin structures of cancer cells were intimately linked to drug resistance. However, 3D chromatin structures in drug-tolerant cancer cells at single-cell resolution haven't been elucidated. Here we performed single-cell Hi-C (scHi-C) analysis to examine the 3D chromatin structures in three stages of breast cancer cells. Overall design: To fully understand the 3D chromatin structures of drug-tolerant cancer cells at single-cell resolution, we designed scHi-C approach for analyzing a breast cancer cell model system, MCF7, MCF7M1 and MCF7TR cells. A total of 293 cells (89 MCF7 cells, 91 MCF7M1 cells, 113 MCF7TR cells) were used for scHi-C profiling.