Meanwhile, in New Jersey, Richard Swarm and his group were working on the characterization of the ECM of chondrosarcomas, unraveling the interactions between collagen, hyaluronic acid, and associated proteins. In doing so, they isolated a gel with characteristics of the basement membrane and named it EHS sarcoma using the initials of the three investigators—Engelbreth, Holm, and Swarm (Swarm, 1963; Orkin et al., 1977)—who discovered and defined it. This was the discovery of what we know today as Matrigel (Kleinman and Martin, 2005), or otherwise, more accurately laminin-rich gel. In the seminal paper of Orkin et al. (1977), the researchers determined that collagen IV is a major constituent of the matrix isolated from the tumor. Laminin was characterized two years later, also extracted from the matrix of the EHS sarcoma (Timpl et al., 1979). Antibodies raised against laminin determined that it was a constituent of basement membranes in normal tissues. Fibronectin had been discovered in 1973 in the context of cultured cells (Gahmberg and Hakomori, 1973; Hynes, 1973; Ruoslahti et al., 1973) and was found to be a major component of basement membrane (Stenman and Vaheri, 1978).
