RG108 is a small molecule inhibitor primarily used in epigenetic research due to its ability to inhibit DNA methyltransferases (DNMTs), especially DNMT1. It is widely applied in studies involving DNA methylation, a key regulatory mechanism in gene expression. By blocking DNMT activity, RG108 can induce demethylation of promoter regions, leading to the reactivation of silenced tumor suppressor genes in cancer cells. This makes it a valuable tool in cancer research, particularly in exploring epigenetic therapies for tumors driven by aberrant DNA methylation. It is also used in cellular reprogramming and stem cell studies, where modulation of DNA methylation can influence cell differentiation and pluripotency. Unlike older DNMT inhibitors such as 5-azacytidine, RG108 does not require incorporation into DNA, reducing genotoxic effects and offering a more specific mechanism of action. This feature enhances its utility in mechanistic studies where clean pharmacological inhibition is needed. Due to its cell permeability and relatively low toxicity, RG108 is suitable for in vitro experiments in various cell lines. However, its use in vivo is limited by stability and bioavailability issues, so it remains primarily a research compound rather than a therapeutic agent. Overall, RG108 supports the development of novel epigenetic drugs and deepens understanding of methylation-related gene regulation.