Book excerpt: Hepatobiliary tumor, mainly including hepatocellular carcinoma, cholangiocarcinoma and gallbladder cancer, is a group of highly aggressive malignancies. Hepatocellular carcinoma, cholangiocarcinoma and gallbladder cancer have different biological characters, histopathological traits, and treatment strategies, but have similar clinical features such as silent early symptom and extremely poor prognosis. The diagnostic, predictive or prognostic tumor biomarkers of hepatobiliary cancers are in unmet need. In contrast to the poor outcome, the treatment options to hepatobiliary cancers are very limited. It is still controversial about the effects of chemotherapy and radiotherapy of hepatobiliary cancer. FDA-approved targeted drugs are only Sorafenib and Lenvatinib for hepatocellular carcinoma, and Pemigatinib for cholangiocarcinoma. Unfortunately, these drugs are only effective for 5%-30% patients. Therefore, more attention should be called upon on investigating effective biomarkers and drug targets, stratifying high-risk patients, guiding precise treatments, and developing therapeutic strategies for hepatobiliary cancers. This Research Topic aims at discussing the current knowledge and proceedings of diagnostic, predictive and prognostic tumor biomarkers in hepatobiliary cancer, and presenting the recent advances on new drug targets and potential targeted therapies of hepatobiliary cancer. We welcome submissions of Review, Mini-Review, Clinical Trial and Original Research articles covering, but not limited to, the following topics: 1. new diagnostic/prognostic factors, biomarkers and/or risk factors in hepatobiliary tumors 2. new drug targets, and oncogenic or tumor suppressive molecular mechanism of the novel targets 3. new intervention or targeted therapy in hepatobiliary tumors 4. new findings of bioinformatics or high-throughput methods such as mass spectrometry and genome-wide association studies or which may help screen the potential biomarkers of hepatobiliary tumors 5. clinical studies such as cohort study or RCT to identify new risks or treatment therapies in hepatobiliary tumors 6. basic, pharmacological, preclinical or clinical study of potential drugs targeting hepatobiliary tumors Please note: manuscripts consisting solely of bioinformatics or computational analysis of public genomic or transcriptomic databases which are not accompanied by validation (independent cohort or biological validation in vitro or in vivo) are out of scope for this section and will not be accepted as part of this Research Topic.