Improving the Use of Immunotherapy to Treat Liver Cancer

* General inclusion Criteria: 1. Male or female, age \> 18 years 2. Diagnosis or suspected diagnosis of hepatocellular carcinoma based on imaging * Specific inclusion criteria cohort 1 (retrospective/prospective data may be applicable): 1. Pathologically confirmed HCC 2. Treated with systemic treatment \[tyrosine kinase inhibitor (TKI) or immunotherapy (ICI)\] in the last 7 years and follow-up data (at least one imaging on treatment) available until 01/01/2025 3. Biopsy obtained between 01/01/2018 until 01/01/2025 4. Left-over tissue from previous diagnostic biopsies or resection specimens available 5. Time between biopsy and initiation of systemic treatment \< 1 year 6. Ability to sign informed consent for secondary use of archival tissue and data collection for study-specific research for patients who are alive * Specific inclusion criteria cohort 2 (aHCC \& prospective): 1. Suspicion of hepatocellular carcinoma (imaging criteria or recurrent disease of previously treated HCC) 2. Indication for tumor biopsy per standard of care 3. Eligible for systemic treatment (any) after pathological confirmation of HCC 4. Ability to sign informed consent for primary use of tissue and blood samples and data collection for study-specific research * Specific inclusion criteria cohort 3 (eHCC \& prospective): 1. Suspicion of hepatocellular carcinoma (imaging criteria or recurrent disease of previously treated HCC) 2. Indication for local treatment (resection or ablation) 3. Ability to sign informed consent for primary use of tissue and blood samples and for data collection for study-specific research Due to the observational nature of this study, participation in other (interventional) clinical trials is permitted, if biological materials can be collected per protocol. * General exclusion criteria: 1. Poor liver function and/or performance status which prohibits active treatment 2. Pathologically proven other malignancies of the liver, including primary cholangiocarcinoma or liver metastases 3. Treatment plan other than systemic treatment or local treatment (resection or ablation), such as TACE, TARE, liver transplantation