PDCD1 and cancer: However, these exhausted cells may regain functionality upon the therapeutic use ICB, such as the anti-PDL-1 monoclonal antibody Atezolizumab and anti-PD-1 Nivolumab or Pembrolizumab which have proved particularly effective against cancers expressing mutated ‘neoantigen’ or exhibiting inflamed tumour microenvironments (TME) such as Melanoma for which anti-PD-1 Immunotherapy is now a first-line treatment [10].