FN1 and neoplasm: The desmoplastic stroma of pancreatic cancer, mainly characterized by a dense extracellular matrix and abundant fibroblasts and inflammatory cells, is composed of several types of cells (e.g., fibroblasts, stellate cells, immune cells, and pericytes) and acellular components (e.g., fibrin, collagen, hyaluronic acid, fibronectin, growth factors, and cytokines), which lead to a tumor microenvironment characterized by low pH, hypoxia, and high tumor interstitial fluid pressure [61].