Fig. 2
From: Applications of single-cell sequencing in cancer research: progress and perspectives
Schematic of tumor metastasis and interactions between circulating tumor cells (CTCs) and peripheral cells. a Tumor metastasis is a complex process that includes invasion of the primary tumor border, intravasation, survival in the circulatory system, extravasation and the formation of a micrometastatic niche in distant tissues. b However, CTCs in the circulatory system dynamically interact with peripheral cells, and CNCs are very important. E: estrogen; CTCs: circulating tumor cells; CNCs: circulating tumor cell and neutrophil niches