Representative photomicrographs of protein expression. A-C: calpastatin staining in pancreatic and distal cholangiocarcinoma; A: absence of immunoreactivity in papillary pancreatic adenocarcinoma; B: strong cytoplasmic immunoreactivity in moderately differentiated cholangiocarcinoma; C: staining in mucinous secreting adenocarcinoma. D-F: calpain-1 staining in pancreatic carcinoma; D: absence of immunoreactivity in poorly differentiated adenocarcinoma; E: moderate cytoplasmic and nuclear staining in moderately differentiated adenocarcinoma; F: weak dot cytoplasmic immunoreactivity in pancreatic adenocarcinoma. G-I: calpain-2 staining in pancreatic carcinoma; G: absence of immunoreactivity in moderately differentiated adenocarcinoma; H: moderate cytoplasmic and nuclear activity in poorly differentiated adenocarcinoma; I: staining in mucinous secreting adenocarcinoma. Photomicrographs are at 10x magnification with 20x magnification inset box where scale bar shows 100μm.