This project includes two studies: 1) the Shanghai Biliary Tract Cancer Study, 2)the Chile Gallbladder Cancer Study. These studies complement each other and will provide unique insight into the etiology of biliary tract cancer. The Shanghai Study includes more than 3,000 subjects, including over 600 biliary tract cancer patients, 900 gallstone patients, and 1,000 healthy controls randomly selected from the population. A structured questionnaire was used to elicit information on epidemiologic risk factors, including smoking, drinking, diet, medical history, and reproductive factors. The study had a strong biochemical and molecular component with an extensive collection of biological samples, including serum, DNA, gallstones, bile, and tissue samples.The Chile Gallbladder Cancer Study includes a pilot study of 120 subjects. The full-scale study will include 4000 cases of gallbladder cancer and 4000 controls enrolled from 12 locations in Chile, which has the highest risk of gallbladder cancer in the world. Similar to the Shanghai Study, the Chile Study will incorporate extensive biospecimen collection. It will complement the Shanghai Study by allowing replication and validation of previous findings, as well as evaluation of unique exposure (i.e. salmonella typhi and heavy metals).