KRAS and carcinoma: K-ras mutation and p53 overexpression are common in small bowel cancers.[2] Impaired small intestinal acyl coA thioesterase synthesis is probably related to the adenoma-carcinoma sequence of small intestinal epithelial tumors.[9] A significant number of small bowel tumors show moderate to strong COX-2 and c PLA 2 expression.[10]