LC3B recruiter 2 (34R) is an LC3B recruiting agent incorporated into the autophagy-lysosome pathway degradation system (ATTEC, Autophagy-Tethering Compounds), with a direct binding affinity for LC3B. It connects via a linker to the CDK9 inhibitor SNS-032, creating an ATTEC capable of targeting and degrading the CDK9 and Cyclin T1 complex, while also inhibiting them. Consequently, LC3B recruiter 2 exerts its function through an LC3B-dependent autophagy-lysosome pathway, interfering with the cancer cell cycle progression, thereby demonstrating antitumor activity.