PDCD1 and juvenile polyposis syndrome: Treatment with PD-L1 further increased osteoclast resorptive activity (8.86% in control vs 23.5% in PJI, p = 0.001), an effect partially mitigated by PD-1 inhibition in the PJI group (23.5% after PD-L1 treatment vs 8.96% after nivolumab treatment, p = 0.002; vs 15.0% after combined PD-L1 and nivolumab treatment, p = 0.106; Fig. 6F).