PADI4 and pancreatitis: PAD4−/− mice with pancreatitis had decreased trypsin (7.25 ± 1.5 vs. 15.7 ± 2.3 μU/ml, p < 0.0001) and amylase (472 ± 242 vs. 1365 ± 322 μU/ml, p < 0.0001) activity levels compared to wild-type controls (Figures 1A,B).