Together with collaborators at Pontifica Universidad Catolica (PUC), we successfully completed a pilot study in Chile that was previously reviewed and approved by SAG and provided baseline data for the proposed study. Our pilot demonstrated high recruitment rates in the target enrollment area (80%) and high rates of questionnaire completion (100%), blood collection (78% population-based controls), and participant retention (93% of eligible completed a follow-up visit). Information from the pilot was used to optimize procedures for the longitudinal study. We also found that both gallstones and gallbladder cancer were associated with systemic immune alterations, which as we previously demonstrated, reflect inflammatory changes in the gallbladder detectable in bile. The next step is to demonstrate that these markers precede GDC by longitudinally measuring their levels among gallstone patients.