Survival analysis of BRAF-mutant colorectal cancer classes: multivariate and univariate mixed-effects Cox proportional hazards models. Model I compares BRAF classes across all patients irrespective of additional Ras mutation; model II compares class 1 without Ras vs. class 3 with Ras mutations; model III examines additional Ras mutation status within class 3. All models include study as a random effect. Both univariate and multivariate analyses were performed on identical patient cohorts per model to ensure direct comparability.