ApoCIII-induced apoptosis. INS-1E cells were cultured for 24 hours in the absence or presence of 10 μg/ml apoCIII. Cells were exposed to 10 μM of the p38 inhibitor SB203580 (SB) or 100 μM of the ERK1/2 inhibitor PD98059 (PD) during 0.5 hours prior to apoCIII treatment as indicated. After culture, apoptosis was measured as DNA fragmentation and normalized to DNA content. *P < 0.05 denotes effect of apoCIII.