CPI-203 is primarily used in research settings to study its effects on bromodomain-containing proteins, particularly BRD4. It is a potent inhibitor that helps in understanding the role of these proteins in gene regulation and cellular processes. This compound is valuable in exploring potential therapeutic strategies for diseases like cancer, where BRD4 plays a significant role in tumor growth and progression. Researchers utilize CPI-203 to investigate its impact on epigenetic mechanisms and its potential to disrupt cancer cell proliferation. Its application extends to preclinical studies aimed at developing targeted therapies for various malignancies.