Nutlin-3b is primarily used in research to study its role as an inhibitor of the MDM2-p53 interaction. By blocking this interaction, it activates the p53 pathway, which is crucial for tumor suppression. This makes it a valuable tool in cancer research, particularly in understanding mechanisms of apoptosis and cell cycle regulation in tumor cells. Additionally, Nutlin-3b is utilized in preclinical studies to explore its potential as a therapeutic agent in cancers where p53 is still functional, offering insights into targeted cancer therapies. Its application extends to studying drug resistance mechanisms and developing combination therapies to enhance treatment efficacy.