SRP409338 PRJNA904505 4-1BB agonist combined with PD-L1 antibody in the treatment of murine B-cell lymphoma. Although PD-1/L1 mAb have demonstrated clinical benefits in certain cancer types, low response rate and resistance remain the main challenges for the application of these immune checkpoint inhibitors (ICIs). As a costimulatory molecule, 4-1BB could enhance T cell proliferation and activation. Herein, the synergetic antitumor effect and underlying mechanism of 4-1BB agonist combined with PD-1/PD-L1 blockade were determined in B-cell lymphoma (BCL).