Background/Aims: To evaluate the causal correlation between complement components and non-viral liver diseases and their potential use as druggable targets. Methods: We conducted Mendelian randomization (MR) to assess the causal role of circulating complements in the risk of non-viral liver diseases. A complement-centric protein interaction network was constructed to explore biological functions and identify potential therapeutic options. Results: In the MR analysis, genetically predicted levels of complement C1q C chain (C1QC) were positively associated with the risk of autoimmune hepatitis (odds ratio 1.125, 95% confidence interval 1.018–1.244), while complement factor H-related protein 5 (CFHR5) was positively associated with the risk of primary sclerosing cholangitis (PSC;1.193, 1.048– 1.357). On the other hand, CFHR1 (0.621, 0.497–0.776) and CFHR2 (0.824, 0.703–0.965) were inversely associated with the risk of alcohol-related cirrhosis. There were also significant inverse associations between C8 gamma chain (C8G) and PSC (0.832, 0.707–0.979), as well as the risk of metabolic dysfunction-associated steatotic liver disease (1.167, 1.036–1.314). Additionally, C1S (0.111, 0.018–0.672), C7 (1.631, 1.190–2.236), and CFHR2 (1.279, 1.059–1.546) were significantly associated with the risk of hepatocellular carcinoma. Proteins from the complement regulatory networks and various liver diseaserelated proteins share common biological processes. Furthermore, potential therapeutic drugs for various liver diseases were identified through drug repurposing based on the complement regulatory network. Conclusions Our study suggests that certain complement components, including C1S, C1QC, CFHR1, CFHR2, CFHR5, C7, and C8G, might play a role in non-viral liver diseases and could be potential targets for drug development.

The rare endocrine and metabolic diseases, due to their varieties, face many challenges in the study of clinical diagnosis, pathogenesis, and treatment. In the past a couple of years, the research on rare endocrine and metabolic diseases has been gradually improved. The diagnosis has made great progress. The research into molecular mechanism of rare endocrine and metabolic diseases has significantly advanced. The effort in exploring the breakthroughs and progress in therapeutic methods based on the pathogenesis of the diseases has also made. This article provides a brief overview of the current status of research into diagnosis, mechanism, and treatment of rare endocrine and metabolic diseases. In addition, the article points out the problems and challenges and proposes future possibilities.