CASP9 and polyarteritis nodosa: In contrast, co-treatment of PAN with RTX (100 μg/ml) was able to reduce the activation levels of all three caspases (cleaved Caspase-8: p < 0.01; PAN + RTX vs. PAN/cleaved Caspase-9: p < 0.01; PAN + RTX vs. PAN)/cleaved Caspase-3: p < 0.05; PAN + RTX vs. PAN), showing apoptosis levels corresponding to healthy controls and RTX-treated cells.