Corning Matrigel matrix is a solubilized basement membrane preparation extracted from the Engelbreth-Holm-Swarm (EHS) mouse sarcoma, a tumor rich in extracellular matrix (ECM) proteins, including Laminin (a major component), Collagen IV, heparan sulfate proteoglycans, entactin/nidogen, and a number of growth factors. https://ecatalog.corning.com/life-sciences/b2b/SEA/en/Surfaces/Extracellular-Matrices-ECMs/Corning%C2%AE-Matrigel%C2%AE-Matrix/p/354262