Breast cancer

accounting for 17.1% of the female cancers

is the most frequently diagnosed malignancy among women in China. Current treatment strategies based on the breast cancer subtype have remarkably improved the prognosis

however

obstacles remain. It’s of great importance to elucidate problems

including the tumor heterogeneity

metastases and therapeutic resistance

to promote therapeutic efficacy. Single-cell RNA sequencing is a novel method that enables unbiased

high-throughput and high-resolution transcriptomic analysis at the single-cell level. It could profile intratumor gene expression features at single-cell resolution and improve our understanding of breast cancer. This review illustrated the application of single-cell RNA sequencing in breast cancer from diverse aspects to obtain further knowledge of this emerging technology and provided new insights into breast cancer research.