Effects of mitogen stimulation on ccp1-induced cell proliferation and cell shape changes. MEF expressing ccp1 and parental MEF were cultured in absence of serum overnight and treated with FGF2 and heparin or 10% serum, for 24 h. (A) One hour pulse label of BrdU was performed and BrdU incorporation was calculated as described before (**p < 0.005). (B) Parental MEF and MEF stably expressing ccp1 were cultured in absence of serum overnight (a-b) and treated with FGF2 and heparin (c-d) or serum (e-f). Upon FGF2 stimulation for 24 h, MEF stably expressing ccp1 showed more drastic changes in cell shape. Similar changes were observed in the presence of serum.