In both studies, comprehensive panel of 17 serum BA (primary, secondary, (un)-conjugated, sulphated) and metabolic biomarkers (inflammation, liver function, dyslipidemia, HbA1c, MetS indicators, hepatitis status) will be assessed using validated methods. Study 2 will also assess expression of liver FXR, a BA receptor gene. Statistical Methods: Study 1 will calculate odds ratios and 95% confidence intervals for circulating BA levels/MetS markers in relation to HCC and GBTC risk by multivariable conditional logistic regression, controlling for potential confounding variables and effect modifiers. Receiver operating characteristics (ROC) analyses will be performed to assess a combination of BA and metabolic markers with best performance to prospectively distinguish between cancer cases and controls. In study 2, GLM (repeated measures) ANOVA will be used to compare pre-/post-surgery changes in biomarkers. BA profiles from both studies, will be compared and correlations between BA and other biomarkers, lifestyle and body size measures will be assessed.