IC261 is primarily utilized in biological research as a potent and selective inhibitor of casein kinase 1 (CK1). It is widely used in studies investigating the role of CK1 in various cellular processes, including circadian rhythms, cell cycle regulation, and Wnt signaling pathways. Researchers employ IC261 to explore its effects on cancer cell proliferation, as CK1 is often implicated in tumor growth and progression. Additionally, it serves as a valuable tool in understanding neurodegenerative diseases, where CK1 activity is linked to pathological mechanisms. IC261's ability to modulate CK1 activity makes it a critical compound for dissecting kinase-related pathways and developing potential therapeutic strategies.