In this study, pancreatitis with abundant infiltration of Foxp3-positive cells developed in poly I:C-treated MRL/Mp mice therefore it may be possible that Tregs were related to the development of pancreatitis in poly I:C-treated MRL/Mp mice and that the function of infiltrated Tregs was different in MRL/Mp and C57BL/6 mice. Here, FOXP3 is linked to pancreatitis.