is increased in metastatic SW620 cells relative to non-metastatic SW480 cells. (A) Detergent extracts prepared from lysates of SW480 and SW620 cells were analyzed by immunoblotting with an affinity-purified anti-DGKζ antibody (top) and an anti-α-tubulin monoclonal antibody (bottom). (B) Graph showing the quantification of DGKζ levels by densitometric analysis of immunoblots. The data were normalized to the level of α-tubulin and expressed as a fold increase relative to the amount in SW480 cells. Values are the average ± S.E.M. of four independent experiments. The asterisk indicates a highly significant difference (P < 0.01) from SW480 cells by Student’s t-test.