Study aim: To compare proteomic profiles of patients with compensated advanced liver disease with and without clinically significant portal hypertension (CSPH) and by analyzing differently expressed proteins to identify potential new serum biomarkers for the early diagnosis of CSPH. Subjects and methods: Patients with compensated advanced liver disease will be included in the study. Two groups will be separated based on the presence of CSPH assessed by hepatic vein pressure gradient. High performance liquid chromatography and mass spectrometry will be used to determine the protein composition of the pooled samples. Bioinformatic tools and literature review will be used to analyze the significance and biologic role of the identified proteins. Expected scientific yield: We expect by analyzing differently expressed proteins and biological processes to identify potential biomarkers of CPSH and to provide additional insight to the pathogenesis of CSPH.