FN1 and neoplasm: The tumor microenvironment includes a non-cellular compartment formed by ECM proteins (i.e., laminin, fibronectin, and collagen) and soluble factors (i.e., cytokines, growth factors, chemokines, exosomes, and miRNAs), and a rich cellular compartment constituted by tumor cells and stromal cells (i.e., fibroblasts, osteoclasts, endothelial cells, and mesenchymal stromal cells) (Manier et al., 2012) (Figure 1).