Copyright: &copy; 2026 Aleid et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.<h4>Background/objectives</h4>Programmed cell death protein-1 (PD-1) and programmed death ligand-1 (PD-L1) inhibitors are widely used in cancer treatment. Here, PDCD1 is linked to cancer.