FN1 and neoplasm: Similarly, tumours have ‘their’ stromal cells which consist of non-malignant cells of the tumour such as cancer-associated fibroblasts (CAFs), specialized mesenchymal cell types characteristic to each tissue environment, innate and adaptive immune cells, vasculature with endothelial cells and pericytes, the extracellular matrix (ECM) consisting of structural proteins (collagen and elastin), specialized proteins (fibrillin fibronectin and elastin) and proteoglycans 2.