Introduction Liver cancer combines two worrying characteristics: a rising prevalence and an alarmingly low 5-year survival rate of 20 %. Development of hepatocellular carcinoma is strongly connected to other liver conditions such as fibrosis and cirrhosis. Causes range from alcohol consumption and toxin ingestion to progressive forms of metabolic-dysfunction associated fatty liver disease (MAFLD). In light of globally increasing in obesity rates, the latter is particularly worrisome. MAFLD encompasses a range of conditions which if left unresolved can trigger liver inflammation and scarring. One of the main local mediators of liver inflammation and fibrosis are hepatic stellate cells (HSC). The activation of these usually dormant (quiescent) cells results in the loss of their intracellularly stored lipid droplets and their trans-differentiation into myofibroblast-like cells. Furthermore, activated HSC play a pivotal role in liver fibrosis by excessive deposition of fibrotic proteins. Therefore, gaining a comprehensive understanding of HSC activation and its potential reversal is crucial for unravelling the complexities of liver diseases, particularly fibrosis. Methods To unravel the intricate pathways involved in HSC activation, we conducted proteomics experiments using a human stellate cell line (LX-2). In vitro activation was achieved by incubation with 10 % fetal bovine serum (FBS) or transforming growth factor beta (TGF-) while cells were deactivated by removing these stimulating agents. Since stellate cells tend to lose their lipid droplets during activation, we also investigated the role of adipose triglyceride lipase (ATGL) in HSC activation by treating the cells with a small-molecule ATGL inhibitor NG-497. Results We identified TGF-alpha as more potent method for activating LX-2 cells and confirmed activation-specific phenotypical changes including increased expression levels of extracellular matrix proteins and proteins involved in migration and cytoskeletal organization. We further revealed that quiescent LX-2 cells display minor differences when ATGL was inhibited, whereas activated cells exhibited more pronounced alterations upon NG-497 treatment. The pathways affected by the inhibition include proteins associated with mitochondrial metabolism and protein biosynthesis. Our data suggests that inhibiting ATGL could result in less pronounced phenotypes of activated HSC by disrupting energy yielding pathways, starving the cells out in the process. However, the observed effects could also root in the distortion of signalling pathways by ATGL inhibition, as it is already known that the loss of ATGL activity can impact PPAR-alpha signalling, thus disrupting mitochondrial substrate oxidation.