Figure 2. Hematoxylin-eosin (H-E) staining of the three tumors: a. Adenocarcinoma in pancreatic cancer (x200); b. Well to moderately differentiated adenocarcinoma in gastric cancer (x100); c. Well to moderately differentiated adenocarcinoma in cecal cancer (x100). Cytokeratin 7 staining of the three cancers. d. Positive in pancreatic cancer (x200); e. Positive in gastric cancer (x100); f. Negative in cecal cancer (x100). CK20 staining of the three cancers: g. Negative in pancreatic cancer (x200); h. Negative in gastric cancer (x100); i. Positive in cecal cancer (x100).