Zhang et al. [59] found that stimulating TLR-4 and Adenylyl Cyclase-Associated Protein 1(CAP1) receptors with resistin (a factor secreted by macrophages in the tumor microenvironment) can activate the STAT3 pathway and endow pancreatic cancer cells with resistance to drug therapy. This evidence concerns the gene TLR4 and familial pancreatic carcinoma.