Besides neo-vascularization within the tumor microenvironment, the extracellular matrix (ECM) provides an important structural scaffold comprising fibrous proteins such as collagens, elastin, laminins, and fibronectin, globular proteins including the IgG superfamily integrins and cellular proteases, for instance MMPs, cathepsins and kallikreins for ECM remodeling [64]. The gene discussed is KLK4; the disease is neoplasm.