Fig. 6.

Schematic plot of multi-step hepatic metastasis of PDAC. To successfully build a second tumor clone, primary tumor cells of PDAC must go through a series of steps including local invasion, intravasation, surviving in the circulation system, extravasation, adapting to survival in new microenvironment, colonization, and outgrowth in liver. This figure was adapted from [43]. The types of cell that presented in tumor microenvironments and pro-metastatic factors marked in the figure were modified according to our findings