GW284543 is a potent and selective inhibitor of DNA methyltransferases (DNMT1 and DNMT3A), key enzymes involved in epigenetic regulation through DNA methylation. It is primarily used in research settings to study the effects of epigenetic modifications on cellular processes, particularly in cancer biology. By blocking DNMT activity, GW284543 enables investigators to explore mechanisms of gene expression, cell proliferation, differentiation, and apoptosis. This compound is essential for identifying potential therapeutic targets in oncology and other diseases driven by aberrant DNA methylation, aiding in the development of novel epigenetic therapies.