GSK343 is primarily used in research settings as a potent and selective inhibitor of the EZH2 enzyme, which is part of the Polycomb Repressive Complex 2 (PRC2). This enzyme plays a critical role in gene silencing through the methylation of histone H3. By inhibiting EZH2, GSK343 helps scientists study the effects of reduced histone methylation on gene expression, particularly in the context of cancer research. It is a valuable tool for understanding the role of EZH2 in tumorigenesis and for exploring potential therapeutic strategies targeting epigenetic regulation in diseases like lymphoma, breast cancer, and other malignancies. Additionally, GSK343 is used to investigate the broader implications of epigenetic modifications in cellular differentiation and development.