Tenascin-C inhibits cell contractility. NIH 3T3 fibroblasts were mixed together with fibrin-FN and fibrin-FN+tenascin-C, 70Ten, 70TenS, BSA, or 70 kDa, and the matrices were allowed to polymerize in a 48-well dish. The matrix was detached from the dish, and the area of the matrix was measured after 4 h, subtracted from the starting area, and expressed as a percentage of the starting area. The data are expressed as the mean ± SEM of triplicate experiments.