Substantial evidence suggests that tumor-derived exosomes participate in and promote the formation of premetastatic niches, preparing a future metastatic site for the influx of tumor cells, engraftment, and the survival of incoming metastatic cells.68, 69, 70 Costa-Silva et al. revealed that pancreatic ductal adenocarcinoma (PDAC)-derived exosomes can be internalized by Kupffer cells, causing the secretion of transforming growth factor β and upregulation of fibronectin production by hepatic stellate cells (HSCs). This evidence concerns the gene FN1 and neoplasm.