Moreover, combined with BTK inhibitor ibrutinib, B4 pronounced significant synergistic inhibition of proliferation in MCL cells.411 Based on structure-activity relationship studies, Jin et al. developed a series of AKT degraders, including MS21, that are more effective in degrading AKT in various tumor cells, including those with PTEN/PI3K mutations, compared to their parent SMIs. Here, AKT1 is linked to mantle cell lymphoma.