Immune checkpoint inhibitors (ICIs), with the localization on T cells, B cells, and dendritic cells (DCs), can block distinct receptors on T cells or tumor cells and prevent T cell inactivation and tumor immune escape, which include programmed cell death 1 (PD‐1; targeted by Nivolumab, Pembrolizumab, Cemiplimab), programmed cell death ligand 1 (PD‐L1; targeted by Atezolimumab, Durvalumab, Avelumab), and cytotoxic T‐lymphocyte antigen 4 (CTLA4; targeted by Ipilimumab, Tremelimumab) [134, 135, 136]. Here, PDCD1 is linked to neoplasm.