PDCD1 and interstitial nephritis: Checkpoint inhibitors targeting immune proteins on T cells, such as programmed cell death 1 (PD-1) protein or its ligand (PDL-1), and cytotoxic T lymphocyte antigen 4 (CTLA-4), are frequently associated with various immune phenomena involving the kidneys, such as interstitial nephritis, TMA, and podocytopathy [36,38,39].