FN1 and neoplasm: Proteomic profiling of the ECM of genetically engineered mouse models of pancreatic ductal adenocarcinomas at different stages of tumor progression revealed that the early stage of PDAC progression was characterized by an increase in the abundance of the glycoprotein fibronectin, the matricellular proteins tenascin-C and thrombospondins 1 and 2, and the ECM cross-linking enzymes lysyl oxidase-like 2 and transglutaminase 2 and a concomitant decrease in the abundance of basement membrane components: alpha chains 1 and 2 of collagen IV and the chains composing the laminin trimer 221 (127).