AGR2 expression in cancer cell lines of the biliary tract. A. AGR2 mRNA levels in six biliary tract cancer cell lines were measured by real-time RT-PCR. The AGR2 transcript levels were normalized against those of the GAPDH. Results shown are means ± standard deviations of (1/2)CT of target - CT of GAPDH of three experiments. B. AGR2 protein expression was detected by western blot analysis with β-actin as a loading control. The result shown is a representative of three experiments. Abbreviations: CBD, common bile duct; GB, gall bladder; AoV, ampulla of Vater; IHD, intrahepatic duct; HDB, hepatic duct bifurcation; WD, well differentiated; MD, moderately differentiated; PD, poorly differentiated .