Acute-on-chronic liver failure (ACLF) is a frequent complication in hospitalised patients with liver cirrhosis. A large body of data has been published in recent years, demonstrating that acute decompensation constitutes a dramatic turning point in the course of cirrhosis, with development of ACLF being the most severe form of acute decompensation (AD).1 Within the last decades, heterogeneous definitions of ACLF have been proposed in different regions of the world, that is, the European European Association for the Study of the Liver - Chronic Liver Failure (EASL-CLIF) definition, the NASCELD definition in North American and the East Asian APASL criteria. Due to those, epidemiological data on ACLF are heterogenous and not easy to compare. In Gut , Mezzano and colleagues have undertaken huge efforts to homogenise and compare the existing evidence.2 They present an extensive systematic review and meta-analysis on the burden of ACLF worldwide (figure 1A), which constitutes the largest epidemiological study on this subject to date.3 The authors were able to identify 30 prospective and retrospective cohort studies from around the world, which include 43 206 ACLF patients and 140 835 patients without ACLF. Strengths of this study are its scale and the robustness of data, which highlight the global significance of ACLF for patients and …