Altered extracellular matrix (ECM) turnover is a central pathological feature of many diseases. The ECM is a meshwork of molecules that provides structural support to cells throughout the body. It consists mainly of two membranes: the interstitial matrix, which is present between parenchymal cells in all major tissue types, and the basement membrane, which is a sheet of ECM that underlies all epithelial and endothelial surfaces. When a bleed occurs in a tissue, the endothelial cell layer is damaged, resulting in exposure of the basement membrane and influx of blood and inflammatory cells into the interstitial matrix of the deeper tissues. Following ECM remodelling of both the basement membrane and the interstitial matrix as part of the normal wound-repair response, a sub-set of proteases is typically over-expressed, resulting in release of protease-specific fragments of signature proteins of the ECM. These fragments may be used as early diagnostic or prognostic serological biomarkers of ECM-related diseases such as fibrosis.