IL33 and acute pancreatitis: Others have shown that IL-33 activates mast cells[21] and that mast cells express IL-33.[4] Several reports have implicated a role for mast cells in exacerbating acute pancreatitis or acute lung injury.[26], [34], [36]–[39] Therefore, we investigated mast cell activation in the pancreas and lung of mice and rats with ligation-induced acute pancreatitis.