The synthesis of many constituents of connective tissues, including glycosaminoglycans (Grossfeld, Meyer, Godman, and Linker, 1957), collagen (Jackson and Smith, 1957; Porter and Pappas, 1959), collagenase (Evanson, Jeffrey, and Krane, 1967) and a protein immunologically cross-reactive with chondromucoprotein (Janis, Sandson, Smith, and Hamerman, 1967), has been widely studied in cell cultures ...