AZ 3146 is primarily used in biochemical research as a potent and selective inhibitor of MPS1 (monopolar spindle 1) kinase. This kinase plays a crucial role in the spindle assembly checkpoint during cell division, making AZ 3146 a valuable tool for studying cell cycle regulation and mitotic processes. Researchers utilize it to investigate the mechanisms of chromosome segregation and to explore its potential in cancer therapy, particularly in targeting cancers with dysregulated cell division. Its application extends to preclinical studies where it helps in understanding the effects of MPS1 inhibition on tumor growth and survival, providing insights into developing novel anticancer strategies.