Mixed effect of cAMP and C60 on TNF-α–induced apoptosis. L929 cells were treated with recombinant TNF-α (250 μg/mL) in the absence or presence of the indicated inhibitors for 18 hours. The sub-G₁ DNA content was quantitated as described in Fig 1. The concentration of the inhibitors used were as follows: forskolin, 10 μmol/L; dbcAMP, 1.0 mmol/L; C₆₀ (C3), 50 μmol/L; C₆₀ (D3), 50 μmol/L; Z-VAD-FK (ICEi), 100 μmol/L.