INS and sarcoma: Although the molecular mechanisms of cell response to photoimmobilized or soluble insulin have not been a purpose/focus of this study, our results are in line with the earlier reports by Ito et al. who found that insulin immobilized on different supports (polystyrene, poly(methyl methacrylate), poly(oxyethylene), polyacrylic acid) stimulates the growth of mouse fibroblasts, bovine endothelial cells, and mouse sarcoma cells (Chen et al., 1997a,b; Ito et al., 1997; Li et al., 1997) and shows different or stronger effects than insulin in solution.