These findings well explain why evolved pro-epithelial phenotypes of DTCs are displayed in the macrometastatic foci that initially originate from extravasated CTCs with pro-mesenchymal phenotypes [319,320] and outgrow from the dormant micrometastasis due to continued evolution [327], a scenario reminiscent of early tumor progression where tumor cells vigorously proliferate, migrate, invade surrounding ECMs, promote angiogenesis when FN expression is downregulated in a pro-epithelial phenotype as aforementioned [54,55,56]. Here, FN1 is linked to neoplasm.