CPI-455 is primarily used in research settings as a potent and selective inhibitor of KDM5 histone demethylases, which are enzymes involved in the regulation of gene expression by modifying histone proteins. Its application is significant in studying epigenetic mechanisms and their role in various biological processes, including cancer development and progression. Researchers utilize CPI-455 to investigate how inhibition of KDM5 enzymes affects cellular differentiation, proliferation, and response to therapies. This compound is particularly valuable in preclinical studies aimed at understanding the potential of targeting epigenetic regulators for therapeutic purposes, such as in cancer treatment. Additionally, CPI-455 helps in exploring the broader implications of epigenetic modifications in diseases and developmental processes.