PDCD1 and lymphoma: Additionally, the clinically relevant anti-human CD27 mAb, varlilumab (Figure 2C), has shown similar synergistic effects with PD-L1 blockade in protecting against lymphoma in human-CD27 transgenic mice, suggesting that the suboptimal T-cell activation observed in cancer patients treated with PD-1 blockade can be improved by a dual approach including PD-1 blockade and CD27 agonism, and providing mechanistic insights into the cooperative nature of these approaches in activating CD8+ T cells [129].