CKI-7 dihydrochloride is widely used in biochemical research as a potent and selective inhibitor of casein kinase I (CKI). It is particularly valuable in studying the role of CKI in various cellular processes, including signal transduction, circadian rhythms, and cell cycle regulation. Researchers employ it to investigate the phosphorylation mechanisms mediated by CKI and its impact on protein function. Additionally, it is utilized in studies exploring the involvement of CKI in diseases such as cancer and neurodegenerative disorders, providing insights into potential therapeutic targets. Its inhibitory properties make it a critical tool for dissecting the biological functions of CKI isoforms in both in vitro and cellular models.