Multi-centre data show cell-free DNA methylation assays achieve phase-appropriate performance for detection and surveillance, and emerging prospective studies in HCC indicate that ctDNA status and dynamics stratify molecular residual disease and predict recurrence beyond conventional markers (Wehrle et al., 2024; Ren et al., 2024; Hu et al., 2025; Abdelrahim et al., 2025); embedding these signals with AFP/PIVKA-II kinetics and imaging trends allows AI models to generate calibrated, interval-specific relapse probabilities suitable for risk-stratified follow-up and trial triage. Here, AFP is linked to hepatocellular carcinoma.