Pancreas histology and expression of NF-κB and P-ERK. A) H&E. Representative sections of normal adjacent pancreas upon sacrifice at day 219 [d219]), mPanIN-1 (asterisk) and −2 (black arrowhead) at d271, and pancreatic ductal adenocarcinoma at d258 are shown (200X magnification). B) NF-κB. Pancreatic tissue sections were immunostained with a NF-κB specific antibody. Representative images of normal adjacent pancreas at d231, mPanIN-1 (asterisk) and −2 (black arrowhead) at d226, and adenocarcinoma at d239 are shown (200X magnification). NF-κB is expressed in mPanINs and tumor cells (brown). C) P-ERK. Positive P-ERK staining (brown) was localized to the mPanINs (d226) and tumor cells (d295) but was absent in normal adjacent pancreas (d226) (200X magnification).