PDCD1 and neoplasm: Tyrosine kinase inhibitors (TKIs) targeting the vascular endothelial growth factor (VEGF) pathway improved outcomes in patients with metastatic renal cell carcinoma (mRCC), but most patients develop resistance to these antiangiogenic agents.1–6 Immune checkpoint inhibitors (ICIs) targeting the programmed cell death-1 (PD-1) receptor or its ligand (PD-L1) produced durable responses in different types of tumours, including mRCC.7–9