Examining heterogeneity of stromal cells in tumor microenvironment based on pan-cancer single-cell RNA sequencing data

Tumor tissues contain both tumor and non-tumor cells, which include infiltrated immune cells and stromal cells, collectively calledthe tumor microenvironment (TME). Single-cell RNA sequencing (scRNAseq) enables the examination of heterogeneity of tumorcells and TME. In this review, we examined scRNAseq datasets for multiple cancer types and evaluated the heterogeneity of majorcell type composition in different cancer types. We further showed that endothelial cells and fibroblasts/myofibroblasts in differentcancer types can be classified into common subtypes, and the subtype composition is clearly associated with cancer characteristic andtherapy response.