Heterogeneity is one of the most important characteristics of solid tumors. Therefore

it is essential to identify different cell subsets and related gene expression levels in solid tumor and its microenvironment. Single-cell sequencing uses DNA second-generation sequencing technology to analyze the DNA

RNA or DNA methylation level of a single cell

reveal its genome

transcriptome and epigenetic characteristics

and understand the state and function of a single cell. Single-cell sequencing can not only further identify the heterogeneity of cells in solid tumors

but also help clarify the molecular mechanisms of tumor development

metastasis

drug resistance and immune escape

making clinical diagnosis

treatment and prognosis of solid tumors more accurate. This article briefly summarized the advances of single-cell sequencing

and reviewed the application and progress of single-cell sequencing in solid tumor research.