Our data corroborated previous observations [19] showing downregulation of the phosphorylation of ERK1/2 in adenomas and in early-phase adenocarcinomas which, based on our in vitro data, could be caused by ROS-mediated downregulation of the RAS-BRAF-MEK1/2-ERK1/2 signaling cascade. This evidence concerns the gene MAPK3 and adenocarcinoma.