PDCD1 and neoplasm: PD-1 inhibitors, such as Nivolumab (Opdivo) and Pembrolizumab (Keytruda), and PD-L1 inhibitors, such as Atezolizumab (Tecentriq) and Durvalumab (Imfinzi), disrupt this interaction, restoring T cell function and promoting anti-tumour immunity [52].