PDCD1 and neoplasm: For instance, immune checkpoint inhibitors (ICIs) targeting programmed cell death protein 1 (PD-1), programmed cell death-Ligand 1 (PD-L1), and cytotoxic T lymphocyte-associated antigen-4 (CTLA-4), can reverse the tumor-induced metabolic restriction of T cell glucose, leading to the restoration of anti-tumor effects (Kraehenbuehl et al., 2022).