Inhibition of PEL cell proliferation induced by ciglitazone and rosiglitazone as measured by MTS assay. Shown in each panel (y-axis) is the absorbance at 490 nm in vehicle (DMSO) without drug (♦) or presence of 100μM ciglitazone (A-D, ■) or 150μM (E-F, ■) or 200μM rosiglitazone (E-F, ●) versus time in hours after drug treatment (x-axis). Each data point is the average of triplicate or quadruplicate measurements. Error bars represent the SD and in most cases are smaller than the symbol.