The ANN revealed the most informative signs of possible choledocholithiasis were the level of bilirubin, alanine aminotransferase, the diameter of the common bile duct, the number of stones in the gall bladder, the size of the smallest stone, history of biliary colic, history of acute cholecystitis or acute pancreatitis. The gene discussed is GPT; the disease is choledocholithiasis.