For instance, cardiac ECM proteins are markedly less abundant than cytosolic and mitochondrial proteins.46 Thus, studies that use whole tissue lysates for proteomic analysis inevitably mask the identification of the less abundant ECM constituents. With cardiac tissue this is exacerbated due to the higher cellular content.2 Accordingly, methods that enrich for ECM proteins have received considerable interest of late and principally focus on removing plasma contaminants and soluble cellular proteins.57,66