REG4 and gallbladder adenocarcinoma: The positive rate of MK-1 or RegIV expression was significantly higher in gallbladder adenocarcinoma than that in peritumoral tissues (χ2MK-1 = 18.76, P < 0.01; χ2RegIV = 9.92, P < 0.01), denomatous polyp (χ2MK-1 = 9.49, P < 0.01; χ2RegIV = 8.59, P < 0.01) and chronic cholecystitis (χ2MK-1 = 24.11, P < 0.01; χ2RegIV = 19.24, P < 0.01).