REG4 and gallbladder adenocarcinoma: On the contrary, the positive rates of RegIV were significantly lower in the cases of well-differentiated adenocarcinoma, no-metastasis of lymph node, and no-invasiveness of regional tissues than those in the ones of differentiated adenocarcinoma, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma (P < 0.05 or P < 0.01).