Figure 1.

Schematic view of metastatic process. Metastatic cascade starting from primary tumor site to distant sites via (A) escape of tumor cells from the primary tumor site, (B) infiltration of tumor cells into adjacent tissue, (C) crossing of endothelial barrier and entry into blood or lymphatic vessel, (D) metastatic spread of circulating tumor cells (CTCs) through blood or lymphatic vessel, and (E) extravasation as disseminated tumor cells (DTCs) and formation of metastasis at distant site (modified according to [9]).