NID1 and sarcoma: The matrigel obtained from Engelbreth‐Holm‐Swarm (EHS) mouse sarcoma is composed of laminin (60%), collagen IV (30%), heparan sulphate proteoglycans (8%) and entactin or nidogen (1%).46 Also the commercial geltrex matrix contains laminin, collagen IV, entactin and heparin sulphate proteoglycans.