TLR4 and pancreatic adenocarcinoma: In pancreatic adenocarcinoma (PDAC), tumorigenesis is promoted by suppression of the function of DCs by exosomes carrying miR-203, which downregulates Toll-like receptor 4 (TLR4), tumor necrosis factor-α (TNF-α), and IL-12 expression, and ultimately prevents antigen presentation by DCs (95).