NOS1 and intrahepatic cholangiocarcinoma: The researchers found that ICC, 5-HT2B receptor expression, 5-HT levels, nNOS neurons, CHAT neurons, and GDNF protein expression were all decreased in the diabetic and sham GES groups compared to control (p-values: <0.008, <0.006, <0.001, 0.002, <0.001, <0.001, respectively).