PFI-1 is primarily used in research settings as a selective inhibitor of the BRPF1 bromodomain, which plays a role in epigenetic regulation. Its application is significant in studying chromatin remodeling and gene expression processes. Researchers utilize PFI-1 to explore its potential in modulating BRPF1 activity, which is implicated in various diseases, including cancer. By inhibiting BRPF1, PFI-1 helps in understanding the role of bromodomain proteins in tumor growth and progression, making it a valuable tool in cancer biology and drug discovery studies. Additionally, it aids in investigating the broader implications of epigenetic modifications in cellular functions and disease mechanisms.