Fig. 7. Effect of the cytokine TNF or the chemotherapeutic agent doxorubicin on viability of C2/CEP4 and C2/AS cells. Cells were treated with varying concentrations of TNF or doxorubicin for 2 days, 7 days after plating. Media was removed and replaced with phenol red-free DMEM with XTT reagents, and the conversion to the formazan dye was followed for 60 min. Values shown are means ± SE for three experiments. *,P < 0.05 compared with CEP4 transfected cells.