CRT0066101 (hydrochloride) is primarily utilized in biochemical research as a potent and selective inhibitor of protein kinase D (PKD). Its application is significant in studying cellular signaling pathways, particularly those involving PKD, which plays a role in processes like cell proliferation, apoptosis, and migration. Researchers use it to explore the mechanisms of cancer progression, as PKD is often implicated in tumor growth and metastasis. Additionally, it aids in understanding the role of PKD in cardiovascular diseases, immune responses, and other pathological conditions. The compound is also employed in drug discovery efforts to develop targeted therapies for diseases where PKD activity is dysregulated. Its specificity makes it a valuable tool for dissecting PKD-related functions in various biological contexts.