PDCD1 and nasopharyngeal carcinoma: In the last few years, immune checkpoint inhibitors (ICIs) including the programmed cell death protein 1 (PD1), programmed cell death ligand 1 (PD-L1), and the cytotoxic T-lymphocyte antigen 4 (CTLA4) inhibitors, have rapidly changed the therapeutic landscape of different malignancies, such as melanoma, lung carcinoma, and nasopharyngeal cancer (Isaacs et al., 2021).