Growth of NIH–PPARγ, NIH-vector, or HIB1B cells in the presence or absence of PPARγ ligands. The same number of NIH–PPARγ, NIH-vector, or HIB1B cells were cultured either in the presence or absence of PPARγ ligands. Cell numbers were determined at the indicated time points. (A) Cumulative growth of cells untreated or treated with 5 μm pioglitazone is shown. (B) Percent decrease of the cell numbers in the pioglitazone-treated plates (solid bars) relative to the untreated plates (open bars) is shown. (C) Exponentially growing cells were treated without or with two members of thiozolidinediones, pioglitazone (5 μm) (solid bars) or BRL49653 (1 μm) (open bars) for 5 days and cell numbers were determined. The effect of ligands on cell growth is represented as percentage decrease in cell numbers in the treated plates relative to untreated control plates.