PCI-34051 is primarily utilized in research settings as a selective inhibitor of histone deacetylase 8 (HDAC8). Its application is significant in the study of cancer biology, particularly in understanding the role of HDAC8 in tumor growth and progression. Researchers use it to explore potential therapeutic strategies for cancers where HDAC8 activity is implicated, such as T-cell lymphomas and neuroblastoma. Additionally, it aids in investigating the epigenetic mechanisms underlying gene expression regulation, providing insights into cellular differentiation and development. Its specificity makes it a valuable tool for dissecting the biological functions of HDAC8 in various disease contexts.