PF-4800567 is primarily used in scientific research as a selective inhibitor of casein kinase 1 epsilon (CK1ε), an enzyme involved in the regulation of circadian rhythms and various signaling pathways. Its main application lies in studying the role of CK1ε in cellular processes, particularly in models of neurological and sleep-related disorders. Researchers use PF-4800567 to modulate circadian clock function, helping to investigate potential therapeutic strategies for circadian rhythm disruptions. It is also employed in pharmacological studies to understand the impact of CK1ε inhibition on Wnt signaling and other pathways linked to neurodegenerative diseases and cancer. Due to its specificity, it serves as a valuable tool compound in target validation and mechanistic studies in preclinical research.