Alteration of the cytoskeleton and cell-substratum adhesion are important in the progression of renal carcinoma. We have previously shown that treatment of normal human renal epithelium with phorbol esters mimics the changes seen in renal carcinoma cells. In this study we have demonstrated that the phorbol ester-induced cytoskeletal reorganization is inhibited in the presence of deoxyglucose but not by cycloheximide. We have also shown that treatment of cells with cytochalasin B results in the formation of immature stress fibres restricted to the cell-substratum contact regions. These results suggest that the actin filaments elongate from the focal contacts and that structural rearrangement caused by phorbol esters is an energy-dependent phenomenon but is independent of de novo protein synthesis.